William Lamb was born October 15, 1855, in Lisbon, New London County, Connecticut.
The 1870 United States census showed William Lamb (age 15, born in Connecticut, farm laborer) living with his parents Owen (age 55, born in Ireland, farmer) and Eliza (age 53, born in Ireland) in Greensburg Township, Knox County, Missouri. His other siblings were John (age 24, born in Ireland, farmer), Patrick (age 22, born in Ireland, farmer), Michael (age 18, born in New Hampshire, farm laborer), Eugene (age 12, born in Connecticut), Peter (age 10, born in Connecticut), and Mary (age 10, born in Connecticut).
The 1880 United States census showed William Lamb (age 24, born in Connecticut, brick manufacturer) living in Moorhead, Minnesota.