William Lamb was born 23 March 1835 in Campsie, north of Glasgow, Scotland. He was likely named after his paternal grandfather, who was also William Lamb. He arrived in New York about 1837 with his parents Jane Mckay and Thomas Lamb.
As a child he would have been witness to his father's work ethic, his mother's housekeeping, and the arrival of his siblings, five of whom grew to adulthood in New York. His brother Thomas was born in 1841, although a New York death record suggests that the family lost another son in 1837, shortly after their arrival. Thomas shared his name with their father and maternal grandfather.
By the time the 1850 census was taken, William was already working as a clerk at 15. His father was a mason, and there were children at home: Thomas, 10, Catherine, 8, Jane, 4, and Elizabeth, 1. The families in the neighborhood included more masons from Scotland, as well as Irish, English, and American-born blacks. Ten years later, William and his brother Thomas were both masons. According to "A History of Long Island" he apprenticed under Thomas Gibbons.
Foreign-born William served in the 47th Regiment of Volunteers during the Civil War. He enlisted with the rank of Sergeant in A Company on May 27, 1862 and left for Fort McHenry, Baltimore on the 30th. He was elevated to Captain for bravery in the field. The Company mustered out September 1.
The brothers formed a business partnership: W & T Lamb with offices in Brooklyn and New York. Over the succeeding years they secured contracts for many significant buildings, including schools and banks. William continued to live at home until his marriage in 1872 to Mary Louise Wurster when he was about 37. She was the daughter of Bavarian immigrants, born in New York in 1844.
The couple had five daughters and a son, arriving at regular two year increments between 1874 and 1883. With improvements in health and circumstance, no children were lost at birth. Their children were: Louisa, Janet, Jessie, Gertrude, Katherine and William Frederick. In 1880 the census tells us that they employed two servants. Thomas lived nearby on Rodney Street with his wife and son, the third Thomas Lamb, and a Danish servant. Mary Louise's brother Frederick Wurster had a foundry, also in Brooklyn. While the Lambs prospered in construction, Wurster went into politics and became the last mayor of Brooklyn in 1895.
William Lamb was active in his Presbyterian Church and a trustee for several banks. He remained active in Veteran's organizations. He frequented the Hanover Club and had traveled to Europe with friends. When he died in 1903, the New York Times said he was "one of the most widely known building contractors in Brooklyn."
The Lambs rose from their immigrant roots to New York's high society at the turn of the 20th century. They provided for their children such that a daughter could tour Europe, and a son attend Williams College, Columbia and Beaux Arts in Paris. Nonetheless, William's life was at least 10 years shorter than his father's!