Lawrence was a soldier, lawyer and politician. Records and information about his early life is sketchy and inconsistent as there were many William Lawrences in Texas, but by 1836 he was known to be in Galveston. He was appointed quartermaster for Galveston and often had to front his own funds to purchase supplies. He was also known to quarrel with James Morgan, the commandant of Galveston. After leaving service in 1838, he moved to Harrisburg. He served two terms as a Congressman and then three terms as a Senator representing Harris, Galveston and Liberty Counties. Lawrence died in either 1850, 1853, or 1871.