Horace Greeley, The American Conflict: A History of the Great Rebellion in the United States of America, 1860-65: its Causes, Incidents, and Results: Intended to exhibit especially its moral and political phases with the drift and progress of American opinion respecting human slavery from 1776 to the close of the War for the Union. Volume I.

[187] He accordingly put his column in motion on the 8th of that month, crossing the arid waste, over one hundred miles wide, that stretches south-westward nearly to the Rio Grande, and reached the bank of that river, opposite Matamoras, on the 28th. Here¹ he erected Fort Brown, commanding Matamoras — the Mexicans, under Ampudia, being at the same time engaged in throwing up batteries on their side. These being completed, Ampudia (April 12th) addressed Gen. Taylor, requiring him to return to the Nueces forthwith, there to remain “while our Governments are regulating the pending question relative to Texas;” with a warning that his refusal would be regarded by Mexico as a declaration of war. Gen. Taylor courteously replied that he was acting under instructions that were incompatible with the Mexican's requirement. Ampudia was soon after superseded by Arista, who, early in May, crossed the Rio Grande at the head of 6,000 men, and, on the 8th, attacked Gen. Taylor's 2,300 at Palo Alto, and was badly defeated. Retreating to a strong position at Resaca de la Palma, a few miles distant, he was there attacked next day by Gen. Taylor, who routed his forces, after a sharp conflict, and drove them in disorder across the river. The Mexican loss in these two affairs was 1,000 men, with eight guns, and a large amount of baggage. The undisturbed possession of the entire left bank of the Rio Grande was among the “spoils of victory.”

President Polk (May 11th) communicated some of these facts to Congress in a Special Message, wherein he averred that the Mexicans had “at last invaded our territory, and shed the blood of our fellow-citizens on our own soil.” Congress, two days afterward, responded, by the passage of an act, calling out 50,000 volunteers, and appropriating $10,000,000 for the prosecution of the struggle thus begun, with a preamble, running,

Whereas, by the act of the Republic of Mexico, a state of war exists between that Government and the United States, Be it enacted, etc.

Only 14 votes in the House, and 2 in the Senate were cast against this bill, though several members (among them Mr. Calhoun) refused to vote on it at all; and a motion in the House to strike out the preamble was sustained by nearly every member elected as a Whig.

Congress remained in session till the 10th of August; before which time, it had become evident that Mexico, distracted and enfeebled by so many revolutions, could make no effective resistance to the progress of our arms. President Polk, not without reason, believed that a treaty of peace might be negotiated with her rickety government, whereby, on the payment of a sum of money on our part, not only the boundary of the Rio Grande, but a very considerable