On the next day (18th) the position of the batteries was definitely fixed. In the afternoon I was ordered by Colonel Totten to arrange at the Engineers’ Depot (on the beach) tools for a working party of 200 men—and be ready to conduct it as soon as it was dark to the proper position. The working party (3rd Artillery, Marines, and 5th Infantry—all under Colonel Belton) did not arrive until long after dark—and it was quite late when we arrived at the position for the batteries. I was placed in charge of Mortar Battery No. 1—G. W. in charge of No. 2—a parallel was also made across the little valley. Each of these batteries was for three mortars. No. 1 was formed by cutting away the side of a hill, so that we had merely to form the epaulments[35] and bring the terreplein[36] down to the proper level—the hill sheltering us from the direct fire of the Castle and Santiago. So also with No. 2—which was made in the gorge where the road to the cemetery crossed the ridge on left of valley.
The tools for [the] working party were arranged on the beach in parallel rows of tools for 20 men each and about four feet apart, so that they might take up the least possible space. Each man was provided with a shovel and either a pick, axe, or hatchets (about 140 picks and mattocks). The party was conducted in one rank, by the right flank. The men were well covered by daylight.
[March] 19th. Mason, Foster, and I think [I. I.] Stevens, relieved Captain Lee, Beauregard, Smith and myself at 3 A. M. During the day they continued the excavation of the two batteries and the short parallel across the valley. The enemy kept up a hot fire during the forenoon but injured no one. During the evening of this day Smith laid out and commenced the parallel leading from No. 1 to the position afterward occupied by the 24 pounder battery. The work was difficult on account of the denseness of the chaparral and the small number of workmen. The parapet was made shot proof (or sufficiently so to answer the purpose of covering the morning relief) by daybreak. The enemy fired grape etc. for a short time, but not sufficiently well aimed or long enough kept up to impede the progress of the work. The battery known as the Naval Battery was commenced on this same night. The enemy were kept in entire ignorance of the construction of this battery until the very night before it opened, and then they only discovered that something was being done there—they did not know what. The Mexican Chief Engineer told Colonel Totten of this fact after the capitulation.
[March] 20th. The construction of the parallel and of the mortar batteries Nos. 1 and 2 was carried on during this day. By 3 P. M., when Mason and myself went out there—the parallel was finished—the excavation of the two batteries completed—the sandbag traverses in No. 2 finished—those in No. 1 very nearly so. We were to lay out and excavate the positions for the two magazines of each battery, to commence Mortar Battery No. 3 (for four mortars), lay the platforms and place the magazine frames—which were to be brought out at night fall. By the direction of Mason, I had the positions of the magazines prepared and laid out before dark. Colonel Totten came out and directed me to lay out No. 3. I also laid out the boyau[37] leading from 1 to 2. Mason took charge of the magazines 1 and 2 and directed me to take charge of No. 3. I employed four sets of men on the battery at the same time—one set throwing the earth from the rear of the parallel upon the berm[38]—a second on the berm disposing of this earth thrown on the berm—a third set working at the rear of the battery, excavating toward the front, these threw the earth so as to form slight epaulments, and in rear. A fourth set were employed in making the excavations for the magazines. A very violent Norther arose which obliged me to employ the first and second sets in front of the battery—they excavating a ditch.
At daylight the parapet was shot proof and the battery required about one hour’s digging to finish it. Owing to some mistake the platforms and magazine frames did not arrive until very late and but little progress was made as far as they were concerned. Had they arrived in time all three batteries could have opened on the afternoon of the 21st. The construction of the battery on the left of the railroad [was] still progressing. They fired rockets etc. at us during the early part of the night.
[March] 21st. During this day not very much was done—some progress was made with the six gun battery—magazines, platforms, etc.
[March] 22nd. Not being aware of a change in the detail I went out at 3 A. M. Found the magazines of No. 2 finished, the small magazines of No. 1 the same. Took charge of large magazine of No. 1—whilst Mason was engaged with those of No. 3. About 8 [o’clock] was informed of change of detail, went to camp and was requested by Colonel Totten to go out to the trenches “extra” and give all the assistance in my power, since the General wished to send in a summons to the town at 2 P. M. and open upon them if they refused to surrender. I went out and was chiefly occupied during the day in covering the magazine of No. 1 with earth. This was done under fire of Santiago and adjacent bastion, which batteries having a clear view of my working party made some pretty shots at us—striking the earth on the magazine once in a while, but injuring no one. At 2 P. M. we were ready to open with three mortars in No. 1—three in No. 2—one in No. 3.—seven in all.
The flag was carried in by Captain Johnston, the enemy ceased firing when they saw it. Colonel Bankhead[39] informed the Commandants of Batteries 1 and 3 that the discharge of a mortar from No. 2 would be the signal to open from all the mortars. The flag had hardly commenced its return from the town when a few spiteful shots from Santiago at my party on the magazine told us plainly enough what the reply had been. Probably half an hour elapsed before a report from No. 2 gave us the first official intimation that General Morales[40] had bid defiance to us, and invited us to do our worst.
The command “Fire!” had scarcely been given when a perfect storm of iron burst upon us—every gun and mortar in Vera Cruz and San Juan, that could be brought to bear, hurled its contents around us—the air swarmed with them—and it seemed a miracle that not one of the hundreds they fired fell into the crowded mass that filled the trenches. The recruits looked rather blue in the gills when the splinters of shells fell around them, but the veterans cracked their jokes and talked about Palo Alto and Monterey. When it was nearly dark I went to the left with Mason and passed on toward the town where we could observe our shells—the effect was superb. The enemy’s fire began to slacken toward night, until at last it ceased altogether—ours, though, kept steadily on, never ceasing—never tiring.
Immediately after dark I took a working party and repaired all the damage done to the parapets by the enemy’s fire, besides increasing the thickness of the earth on the magazines of No. 1. Captain Vinton was killed a short time before dark near Battery No. 3 by a spent shell—two men were wounded by fragments of shells near No. 1. Shortly after dark, three more mortars were put in Battery No. 3—making 10 mortars in all. Captain [John] Saunders was employed upon the 6 gun battery (24 pounders). He revetted[41] it with one thickness of sand bags, all of which fell down next morning. I brought out from the Engineer Depot the platforms for this battery during the night—the magazine frame was brought out next day. The battery on the left of the railroad [was] still progressing, under the charge of Captain [R. E.] Lee, [Lieut. Z. B.] Tower and [G. W.] Smith—who relieved each other.