Before the Texans, before the Rockets, before even the Astros, there were the Oilers.
Upon their inception in 1960, the Houston Oilers were their home city's first big-league professional sports team. They were an instant success, going a combined 20-7-1 and winning the AFL title in each of their first two seasons.
The Oilers persevered for 37 years before moving to Memphis in 1997. Two years later, they jumped again to Nashville and became the Titans.