A substantial number of former Confederates went to Mexico after the Civil War. These exiles either hoped to continue the struggle or were fearful of their future in the United States. Among them were such men as governors Pendleton Murrah of Texas, Henry Allen and Thomas Moore of Louisiana, and Thomas Reynolds of Missouri; former governor Edward Clark of Texas; and officers John B. Clark of Missouri, Danville Leadbetter of Alabama, Cadmus M. Wilcox of Tennessee, Thomas C. Hindman of Arkansas, William P. Hardeman of Texas, and John B. Magruder. Those led by Gen. Joseph Orville (Jo) Shelby, former commander of the "Iron Cavalry Brigade" of Missouri, came to be called the Shelby expedition. Shelby was a wealthy planter from Lafayette County, Missouri. He was born on December 12, 1830, in Lexington, Kentucky, attended Transylvania University, and in 1858 married a distant cousin, Elizabeth Nancy Shelby. A staunch Confederate sympathizer, he once indignantly refused the offer of a commission in the Union Army by his cousin Francis Preston Blair. With no military training he organized and commanded a cavalry company at Newtonia, Missouri, at his own expense, and in June 1862 joined the Confederate forces of Gen. James E. Rains at Van Buren, Arkansas. The Iron Cavalry Brigade operated chiefly in Arkansas and Missouri, participating in all the major engagements in the region. In October 1864 the brigade crossed the Arkansas River into Texas and at the surrender of Gen. Robert E. Lee was at Marshall. Shelby was one of the few Confederate commanders who refused to surrender to the Union forces pursuing him. On June 1, 1865, with his army disintegrating around him, he determined to take as many of his men as would go to Mexico to continue the war. With a few hundred well-disciplined and orderly men, with all their cannons, arms, and ammunition, he marched from Corsicana through Waco, Austin, and San Antonio to Eagle Pass. Prominent persons joined them on the way. While crossing the Rio Grande at Piedras Negras, they sank their Confederate guidon in the river, in what came to be known as the "Grave of the Confederacy Incident."
In Mexico they encountered the rebel forces of Benito Juárez. After selling all their arms to the rebels except their revolvers and carbines, they were permitted to pass to the south. They arrived in Mexico City in mid-August 1865. There they offered their services to Maximilian. Although grateful, the French-installed emperor received them only as immigrant settlers subject to the liberal terms of the Decree of September 5, 1865. Many of Shelby's men accepted and joined in the establishment of the Carlota colony in Córdoba and a colony at Tuxpan. Others joined the army or went to the Pacific coast and sailed to South America or California. Shelby himself occupied the hacienda of Santa Anna and began business as a freight contractor. He moved to Tuxpan in the fall of 1866, left Mexico the next year, and returned to Missouri, where he died in 1897 at the age of 67. Because of the Mexican civil war, robbers, and attacks by dispossessed Indians, the colonies lasted only about a year. Most of the Americans returned to the United States by the end of 1867.