John Baker Omohundro was born July 27, 1846 at "Pleasure Hill," the family home near Palmyra in Fluvanna County, Virginia. It is said that he was not very fond of the schoolroom, to which he had to ride five miles on horseback each way, and was known to "play hooky" upon occasion, arriving home at night with a long string of fish, which he had, somehow "miraculously obtained" during the day. From early youth he was a natural born fisherman, huntsman, horseman and "crack" shot who loved adventure, danger and the great outdoors.

Note: Texas Jack's middle name has sometimes been reported as "Burwell," but his name and birth are recorded in the family Bible as "Baker," his mother's maiden name.