He was elected to represent Sabine County in the House of the Second Congress in September 1837, but he resigned in April 1838 because of illness. Clark was still in Sabine County in April 1850 but probably moved to Nacogdoches County shortly thereafter. In 1859 he purchased the Planter Hotel in Nacogdoches, which he operated until his death, on January 3, 1871. Clark was a Methodist. In 1936 the Texas Centennial Commission placed a marker at the site of the Clarks' last home and a joint monument at the graves of Clark and his wife in Oak Grove Cemetery in Nacogdoches. Clark's son, who was also known as William Clark, Jr., was elected a representative to the state legislature in 1859 and to the Secession Convention in 1861. This man's activities have sometimes been attributed to his father.
31° 36.204, -094° 38.940
Oak Grove Cemetery