My gg-uncle, Captain Sam Willson, Co. F, 1st TX fought at Gettysburg and he was captured on July 3rd during General Farnsworth's cavalry charge. Uncle Sam, disguised as a private, was sent to Ft. Delaware and he escaped between July 7th and July 12th (official Union record). He returned to his unit in Virginia, was re-elected captain and served the remainder of the War.

Here is an account (published in 1911) told by Alfred Cuthbert Sims, a private in Co. F:
http://www.texas-brigade.org/frameset1tex.htm

About this time the battle was raging furiously on our left and from our position we could see our men (Pickett's Division) falling back and we had to retreat to avoid being flanked by the enemy, although there was no engagement on our part of the line.

In the meantime, the 1st Texas had met the Federal Cavalry. They had to deploy as a mere skirmish line to make a front to meet a brigade of cavalry. The Yankees, seeming to be in a state of intoxication, dashed through our line firing right and left. They killed one man in Company A, shooting him through the head, while our boys from behind trees and fence corners with their well directed aim left seventeen dead on the field, among them Gen. Farnsworth, their leader. The Fourth Alabama regiment had been sent to aid the First Texas and it is claimed that some of them killed Gen. Farnsworth, which, however, is a mistake. If there had been any honor in killing a federal general doubtless that honor belongs to the First Texas Regiment. It happened this way: Gen. Farnsworth came dashing up to Corporal A. F. Taylor and demanded his surrender, but Taylor replied with a ball from his Enfield, which took effect in his abdomen just below his belt. The General, looking down, saw his wound, turned his pistol on himself, and shot himself four times and fell from his horse, and if those who came to bury the dead were not personally acquainted with him, they never knew they were burying a general.

If Captain Dan K. Rice is living he can tell something about Gen. Farnsworth's boots. He did not take them off the general, but bought them off a soldier that did, and the fine morocco leather that clothed the feet of a federal general in the battle of Gettysburg, were worn by a Texas captain in the battle of Chickamauga. Captain S. A. Willson and Private T. D. Rock of Company F, having been overcome by heat, sat down just before the regiment met the enemy and when the Yankees ... (attacked they) ... captured them. A few volunteers from the Fourth Alabama regiment and a few grape shot from Riley's battery turned the enemy back and they made their escape around the right wing of Lee's army.