Next Cinco de Mayo, it should be remembered that, without the help of American Civil War Gen. Ulysses S. Grant, it might have taken Mexico years longer to oust the French army and their Austrian puppet-monarch Maximillian I.
Grant considered the 1860s French invasion of Mexico (accompanied, at first, by the Spanish and British) to be a threat to the U.S., even an extension of the Southern rebellion. So at his first opportunity, which didn’t come until immediately after Lee surrendered in 1865, Grant writes in the conclusion of volume two of his "Personal Memoirs," he sent Gen. Phillip Sheridan and an army corps to Texas.
Officially, Grant directed Sheridan to force surrender of the remaining Confederate forces here, but he also told him, unofficially, according to Sheridan’s memoirs, to occupy the northern banks of the Rio Grande. The idea was to make the French think an invasion to overthrow Maximillian was imminent–though the American government actually opposed any such thing.
Somehow all of this has been confused, of late, even by Austin public school academics who should know better, into a claim [subsequently removed from the Web] that the Mexican defeat of the French Foreign Legion at Puebla in 1862 (for which Cinco de Mayo is celebrated) somehow enabled the Union to beat the rebels at Gettysburg a year later. I suppose Puebla may have played some minor role in preventing French supply of arms to the Confederacy. But the claim gets silly when the academics then claim that a grateful President Lincoln promptly sent Sheridan to the Rio Grande. Lincoln was murdered before Sheridan was dispatched by Grant–three whole years after Puebla.
Sheridan got right to work, setting up arms and ammunition dumps on the north bank of the river where Mexican patriots, under Gen. Escobedo, could find them. "During the winter and spring of 1866," Sheridan writes, "[we sent] as many as 30,000 muskets from the Baton Rouge Arsenal alone" to "convenient places on our side of the river." Escobedo’s forces, now sufficiently armed, threw out the French and executed Maximillian. So it wasn’t Lincoln, nor his sucessor, Vice-President Andrew Johnson, but Gen. Grant who should get credit for aiding Mexico, something that ought to be acknowledged on Cinco de Mayo–a holiday celebrated more by Mexican-Americans than by Mexican nationals.
UPDATE: Texana author Mike Cox has a nice review of this book by radio journalist Donald Miles which addresses this issue. Glad to see someone has done it so well.