1840 Census Warren Co, IL in 1840, page 174 - 100020-120010. William was living next to William Despain.
1850 Census: Warren Co, IL page 8-115
1870 Census: Coldbrook, Warren Co, IL film # 280, page 15
1880 Census: Valmont, Boulder Co, CO film T9-0089, page 493. William was 69 and living with his daughter. He was widowed and listed as an inventor.