Invasion of Mexico by Mina.—In the year 1817, when most of the insurgent forces were dispersed, an enterprise of singular boldness was attempted in Mexico, by a foreigner named Don Xavier Mina. His more specific object was to establish the independence of Mexico on a constitutional basis, without an entire severance of the country from Spain. Mina was a nephew of the celebrated general of that name, who so long resisted the French and Spanish royalists in his native country. In May, 1816, he sailed from Liverpool with a small expedition, having a few thousand stand of arms, and also equipages for a body of infantry and cavalry, and arrived in the United States in June. Here he procured the service of several officers, an addition of muskets, and some pecuniary aid from Baltimore and New Orleans. Sailing for the Gulf of Mexico, he did not reach Galveston until November, where he was joined by Aury, the commander of the privateers in that quarter, and by some of the inhabitants; but as it was too late for operations, he passed the winter in Galveston.

Early in the following spring, Mina entered upon the prosecution of his design. But the time chosen by him was unpropitious. The revolutionary cause had fallen to a low point. Mina failed, was taken, and shot. The power of the insurgents was broken, and most of their eminent men were either killed in battle, or shot as traitors, or imprisoned. But the principles of independence were daily gaining ground in the country at large, and the spirit of the revolutionists, though checked for a time, was not subdued, as was proved by subsequent events in Mexican history.

Revolution under Iturbide.—The unfortunate termination of the expedition under Mina, was by no means a termination of the difficulties in which Mexico had long been involved. The next person who largely figured in her affairs was Augustin Iturbide, who had risen, in 1816, by his valor and capacity, to the command of what was called the northern army. In 1820, the cortes having ordered the sale of the church property, the viceroy, Apadoca, refused to acknowledge the cortes; he employed Iturbide to reduce Guerréro, one of the patriot chiefs; but, instead of this, he formed a junction with that chief, and on February 24th, 1821, he proclaimed the independence of his country. Soon after, he took possession of the capital, and, in 1822, May 18th, he usurped the crown, through the subserviency of his troops. He was proclaimed emperor, under the name of Augustin the First.

The next morning congress was convened in extraordinary session. His election to the imperial dignity was proposed and discussed in his presence, and was voted for by a few more than one-half the whole body of delegates. Meanwhile, the friends of liberal institutions, overawed by the power of the usurper, fled to their wonted retreats, until a fitting season should arrive for acting with union and efficiency. The acts of oppression of Iturbide, from this time, continued to increase. He ordered the dissolution of congress, had recourse to forced loans, with other usurpations.

While affairs were in this posture, Santa Anna, who at this time was commanding at Vera Cruz, was suddenly dismissed. Surprised at treatment thus harsh, and as he deemed unjust, Santa Anna excited the garrison to revolt, for the purpose of dethroning Iturbide, and establishing a republican government. While these matters were in progress, Victoria, who for some years had lived in obscurity, made his appearance, and was appointed commander-in-chief of the insurgents. In February, 1823, Echavarri, the commander of the imperialists, joined forces with Victoria and Santa Anna.

Defection now became general among the officers of the army; in consequence of which, Iturbide was obliged to surrender his power. Hastily assembling at Mexico the dispersed members of congress, on the 19th of March, 1823, he tendered them his abdication of the crown. Congress allowed him a yearly pension of twenty-five thousand dollars, on condition of his leaving the Mexican territory for ever. On the 11th of May, he embarked for Leghorn.

Adoption of the Federal Constitution.—A provisionary government was immediately established, and a triplicate executive appointed, consisting of Generals Victoria, Bravo, and Negrete. Measures were at once adopted for the convocation of a new congress, which, upon assembling, entered on the arduous plan of framing a constitution of government. This they did on the federative plan, and on the 2d of February, it was sworn to in the capital, amidst the rejoicings and acclamations of the people. The government soon went into operation, and Victoria was chosen president of the republic, and Bravo vice-president.

Contrary to the decree of perpetual banishment against him, Iturbide returned to Mexico in disguise; but, being discovered, he was shot. This took place on the 10th of July, 1824. Several disturbances had occurred, partly on his account, during his absence; but the republic was now relieved from one great source of disquietude.

The general provisions of the new constitution, as to the distribution of the powers of government into their parts, were the same as those of the constitution of the United States; but they differed as to the right of trial by jury, which was omitted, and the Roman Catholic religion was alone to be tolerated in Mexico.