The expedition against Louisburg, under Major-General Jeffrey Amherst, set sail from Halifax on May 28, 1758. It was joined by the fleet under Admiral Boscawen. The formidable armament consisted of twenty-five sail of the line, eighteen frigates, and a number of bomb and fire ships, with the Royals, 15th, 17th, 22nd, 28th, 35th, 40th, 45th, 47th, 48th, 58th, the 2d and 3d battalions of the 60th, 78th Highlanders, and New England Rangers,—in all, thirteen thousand and nine men. On June 2nd the vessels anchored in Garbarus Bay, seven miles from Louisburg. The garrison, under the Chevalier Ducour, consisted of twenty-five hundred regulars, six hundred militia, and four hundred Canadians and Indians. The harbor was protected by six ships of the line and five frigates, three of the latter being sunk at its mouth. The English ships were six days on the coast before a landing could be attempted, on account of a heavy surf continually rolling with such violence, that no boat could approach the shore. The violence of the surf having somewhat abated, a landing was effected on June 8th. The troops were disposed for landing in three divisions. That on the left, which was destined for the real attack, commanded by Brigadier General Wolfe, was composed of the grenadiers and light infantry, and the 78th, or Fraser's Highlanders. While the boats containing this division were being rowed ashore, the other two divisions on the right and center, commanded by Brigadier Generals Whitmore and Lawrence, made a show of landing, in order to divide and distract the enemy. The landing place was occupied by two thousand men entrenched behind a battery of eight pieces of cannon and swivels. The enemy wisely reserved their fire till the boats were close to the shore, and then directed their discharge of cannon and musketry with considerable execution. The surf aided the fire. Many of the boats were upset or dashed to pieces on the rocks, and numbers of the men were killed or drowned before land was reached. Captain Baillie and Lieutenant Cuthbert of the Highlanders, Lieutenant Nicholson of Amherts, and thirty-eight men were killed. Notwithstanding the great disadvantages, nothing could stop the troops when led by such a general as Wolfe. Some of the light infantry and Highlanders were first ashore, and drove all before them. The rest followed, and soon pursued the enemy to a distance of two miles, when they were checked by the cannonading from the town.

In this engagement the French lost seventeen pieces of cannon, two mortars, and fourteen swivels, besides seventy-three prisoners. The cannonading from the town enabled Wolfe to prove the range of the enemy's guns, and to judge of the exact distance at which he might make his camp for investing the town. The regiments then took post at the positions assigned them. For some days operations went on slowly. The sea was so rough that the landing of stores from the fleet was much retarded; and it was not until the 11th that the six pounder field pieces were landed. Six days later a squadron was fairly blown out to sea by the tempest. By the 24th the chief engineer had thirteen twenty-four pounders in position against the place. The first operation was to secure a point called Lighthouse Battery, the guns from which could play upon the ships and on the batteries on the opposite side of the harbor. On the 12th this point was captured by Wolfe at the head of his gallant Fraser's and flank companies, with but little loss. On the 25th, the fire from this post silenced the island battery immediately opposite. An incessant fire, however, was kept up from the other batteries and shipping of the enemy. On July 9th the enemy made a sortie on General Lawrence's brigade, but were quickly repulsed. In this affair, the earl of Dundonald was killed. There were twenty other casualities. The French captain who led the attack, with seventeen of his men, was also killed. On the 16th, Wolfe pushed forward some grenadiers and Highlanders, and took possession of the hills in front of the Lighthouse battery, where a lodgement was made under a fire from the town and the ships. On the 21st one of the French ships was set on fire by a bombshell and blew up, and the fire being communicated to two others, they were burned to the water's edge. The fate of the town was now almost decided, the enemy's fire nearly silenced and the fortifications shattered to the ground. All that now remained in the reduction was to get possession of the harbor, by taking or burning the two ships of the line which remained. For this purpose the admiral, on the night of July 25th sent six hundred seamen in boats, with orders to take, or burn, the two ships of the line that remained in the harbor, resolving if they succeeded to send in some of his larger vessels to bombard the town. This enterprise was successfully executed by the seamen under Captains Laforey and Balfour, in the face of a terrible fire of cannon and musketry. One of the ships was set on fire and the other towed off. On the 26th the town surrendered; the garrison and seamen amounted to five thousand six hundred and thirty-seven, besides one hundred and twenty pieces of cannon, eighteen mortars, seven thousand five hundred stand of arms, eleven colors, and eleven ships of war. The total loss of the English army and fleet, during the siege amounted to five hundred and twenty-five. Besides Captain Baillie and Lieutenant Cuthbert the Highlanders lost Lieutenant J. Alexander Fraser and James Murray, killed; Captain Donald MacDonald, Lieutenant Alexander Campbell (Barcaldine) and John MacDonald, wounded; and sixty-seven rank and file killed and wounded.

The third expedition was against Fort du Quesne, undertaken by Brigadier General John Forbes. Although the point of attack was less formidable and the enemy inferior in numbers to those at either Ticonderoga or Louisburg, yet the difficulties were greater, owing to the great extent of country to be traversed, through woods without roads, over mountains and through almost impassable morasses. The army consisted of six thousand two hundred and thirty-eight men, composed of Montgomery's Highlanders, twelve hundred and eighty-four strong, five hundred and fifty-five of the Royal Americans, and four thousand four hundred provincials. Among the latter were the two Virginia regiments, nineteen hundred strong, under the command of Washington. Yet vast as were the preparations of the army, Forbes never would have seen the Ohio had it not been for the genius of Washington, although then but twenty-six years of age. The army took up its line of march from Philadelphia in July, and did not reach Raystown until the month of September, when they were still ninety miles distant from Fort du Quesne. It was Washington's earnest advice that the army should advance with celerity along Braddock's road; but other advice prevailed, and the army commemorated its march by moving slowly and constructing a new route to the Ohio. Thus the summer was frittered away. While Washington's forces joined the main army, Boquet was detached with two thousand men to take post at Loyal Hanna, fifty miles in advance. Here intelligence was received that the French garrison consisted of but eight hundred men, of whom three hundred were Indians. The vainglory of Boquet, without the consent or knowledge of his superior officer urged him to send forward a party of four hundred Highlanders and a company of Virginians, under Major James Grant to reconnoitre. Major Grant divided his troops, and when near the fort, advanced with pipes playing and drums beating, as if he was on a visit to a friendly town. The enemy did not wait to be attacked, but instantly marched out of their works and invited the conflict. The Highlanders threw off their coats and charged sword in hand. At first the French gave way, but rallied and surrounded the detachment on all sides. Being concealed in the thick foliage, their heavy and destructive fire could not be returned with any effect. Major Grant was taken in an attempt to force into the woods, where he observed the thickest of the fire. On losing their commander, and so many officers killed and wounded, the Highlanders dispersed, and were only saved from utter ruin by the provincials. Only one hundred and fifty of the Highlanders succeeded in making their way back to Loyal Hanna.

In this battle, fought September 14, 1758, two hundred and thirty-one Highlander's were killed and wounded. The officers killed were Captain William Macdonald and George Munro; Lieutenants Alexander Mackenzie, William Mackenzie; Robert Mackenzie, Colin Campbell, and Alexander Macdonald; and the wounded were Captain Hugh Mackenzie, Lieutenants Alexander Macdonald, Archibald Robertson, Henry Munro, and Ensigns John Macdonald and Alexander Grant.

General Forbes did not reach Loyal Hanna until November 5th, and there a council of war determined that no farther advance should be made for that season. But Washington had plead that owing to his long intimacy with these woods, and his familiarity with the difficulties and all the passes should be allowed the responsibility of commanding the first party. This having been denied him, he prevailed on the commander to be allowed to make a second advance. His brigade was of provincials, and they toiled cheerfully by his side, infusing his own spirit into the men he commanded. Over the hills white with snow, his troops poorly fed and poorly clothed toiled onward. His movements were rapid: on November 15th he was at Chestnut Ridge; and the 17th at Bushy Run. As he drew near Fort du Quesne, the disheartened garrison, about five hundred in number, set fire to the fort, and by the light of the conflagration, descended the Ohio. On the 25th Washington could point out to the army the junction of the rivers, and entering the fortress, they planted the British colors on the deserted ruins. As the banner of England floated over the Ohio, the place was with one voice named Pittsburg, in honor of the great English premier William Pitt.

The troops under Washington were accompanied by a body of Highlanders. On the morning of November 25th, the army advanced with the provincials in the front. They entered upon an Indian path. "Upon each side of which a number of stakes, with the bark peeled off, were stuck into the earth, and upon each stake was fixed the head and kilt of a Highlander who had been killed or taken prisoner at Grant's defeat. The provincials, being front, obtained the first view of these horrible spectacles, which it may readily be believed, excited no kindly feelings in their breasts. They passed along, however, without any manifestation of their violent wrath. But as soon as the Highlanders came in sight of the remains of their countrymen, a slight buzz was heard in their ranks, which rapidly swelled and grew louder and louder. Exasperated not only by the barbarous outrages upon the persons of their unfortunate fellow soldiers who had fallen only a few days before, but maddened by the insult which was conveyed by the exhibition of their kilts, and which they well understood, as they had long been nicknamed the 'petticoat warriors' by the Indians, their wrath knew no bounds. Directly a rapid and violent tramping was heard, and immediately the whole corps of the Highlanders, with their muskets abandoned, and broad swords drawn, rushed by the provincials, foaming with rage, and resembling, as Captain Craighead coarsely expressed it, 'mad boars engaged in battle,' swearing vengeance and extermination upon the French troops who had permitted such outrages. Their march was now hastened—the whole army moved forward after the Highlanders, and when they arrived somewhere about where the canal now passes, the Fort was discovered to be in flames, and the last of the boats, with the flying Frenchmen, were seen passing down the Ohio by Smoky Island. Great was the disappointment of the exasperated Highlanders at the escape of the French, and their wrath subsided into a sullen and relentless desire for vengeance."[138]

The Highlanders passed the winter of 1758 in Pittsburg, and in May following marched to the assistance of General Amherst in his proceedings at Ticonderoga, Crown Point and the Lakes.

Before the heroic action of The Black Watch at Ticonderoga was known in England, a warrant was issued conferring upon the regiment the title of Royal, so that it became known also by the name of 42d Royal Highland Regiment, and letters were issued to raise a second battalion. So successful were the recruiting officers that within three months, seven companies, each one hundred and twenty men strong were embodied at Perth in October 1758. Although Highlanders only were admitted, yet two officers, anxious to obtain commissions, enlisted eighteen Irishmen, several of whom were O'Donnels, O'Lachlans, O'Briens, &c. The O was changed to Mac, and the Milesians passed muster as true Macdonels, Maclachlans, and Macbriars, without being questioned.

The second battalion immediately embarked at Greenock for the West Indies, under the convoy of the Ludlow Castle; and after the reduction of Guadaloupe, it was transferred to New York, and in July, 1759, was combined with the first battalion, in order to engage in the operations then projected against the French settlements in Canada. General Wolfe was to proceed up the St. Lawrence and besiege Quebec. General Amherst, who had succeeded Abercromby as commander-in-chief, was to attempt the reduction of Ticonderoga and Crown Point, and then effect a junction with General Wolfe before Quebec. Brigadier General John Prideaux was to proceed against the French fort near the falls of Niagara, the most important post of all French America.

The army first put in motion was that under Amherst, which assembled at Fort Edward on June 19th. It included the 42nd and Montgomery's Highlanders, and when afterwards joined by the second battalion of the 42nd, numbered fourteen thousand five hundred men. On the 21st, preceded by The Black Watch the army moved forward and encamped on Lake George, where, during the previous year, the army rested prior to the attack on Ticonderoga. Considerable time was spent in preparations for assaulting this formidable post, but on seeing the preparations made by the English generals for a siege, the French set fire to the magazines and buildings, and retired to Crown Point.