This insolent attack upon the Mexican republic, deeply resented in the United States, was allowed to drift in its course until 1865.  At that juncture General Sheridan was dispatched to the Mexican border with a large armed force; General Grant urged the use of the American army to expel the French from this continent.  The Secretary of State, Seward, counseled negotiation first, and, applying the Monroe Doctrine, was able to prevail upon Napoleon III to withdraw his troops.  Without the support of French arms, the sham empire in Mexico collapsed like a house of cards and the unhappy Maximilian, the victim of French ambition and intrigue, met his death at the hands of a Mexican firing squad.

=Alaska Purchased.=—­The Mexican affair had not been brought to a close before the Department of State was busy with negotiations which resulted in the purchase of Alaska from Russia.  The treaty of cession, signed on March 30, 1867, added to the United States a domain of nearly six hundred thousand square miles, a territory larger than Texas and nearly three-fourths the size of the Louisiana purchase.  Though it was a distant colony separated from our continental domain by a thousand miles of water, no question of “imperialism” or “colonization foreign to American doctrines” seems to have been raised at the time.  The treaty was ratified promptly by the Senate.  The purchase price, $7,200,000, was voted by the House of Representatives after the display of some resentment against a system that compelled it to appropriate money to fulfill an obligation which it had no part in making.  Seward, who formulated the treaty, rejoiced, as he afterwards said, that he had kept Alaska out of the hands of England.

=American Interest in the Caribbean.=—­Having achieved this diplomatic triumph, Seward turned to the increase of American power in another direction.  He negotiated, with Denmark, a treaty providing for the purchase of the islands of St. John and St. Thomas in the West Indies, strategic points in the Caribbean for sea power.  This project, long afterward brought to fruition by other men, was defeated on this occasion by the refusal of the Senate to ratify the treaty.  Evidently it was not yet prepared to exercise colonial dominion over other races.

Undaunted by the misadventure in Caribbean policies, President Grant warmly advocated the acquisition of Santo Domingo.  This little republic had long been in a state of general disorder.  In 1869 a treaty of annexation was concluded with its president.  The document Grant transmitted to the Senate with his cordial approval, only to have it rejected.  Not at all changed in his opinion by the outcome of his effort, he continued to urge the subject of annexation.  Even in his last message to Congress he referred to it, saying that time had only proved the wisdom of his early course.  The addition of Santo Domingo to the American sphere of protection was the work of a later generation.  The State Department, temporarily checked, had to bide its time.