Lynde was born in Sherburne, New York.
He graduated from Yale College, in 1838, and Harvard Law School, in 1841, and was admitted to the bar in New York.
He moved to Milwaukee, Wisconsin Territory, shortly thereafter, accompanied by his new wife, Mary.

In 1842 he founded the law firm, Finch & Lynde, with his partner Asahel Finch, Jr. Finch & Lynde survives today as Foley & Lardner, one of the oldest and largest law firms in the country.

Lynde became Attorney General of the Wisconsin Territory in 1844 and United States Attorney for Wisconsin in 1845.
He also served as president of the board of trustees of the Village of Milwaukee.

When Wisconsin was admitted as a state in 1848, Lynde was elected as a Democrat to the United States House of Representatives, one of Wisconsin's first two representatives.
He joined part of the 30th United States Congress from June 5, 1848, till March 3, 1849, representing Wisconsin's 1st congressional district.
He lost his reelection bid for the 31st Congress.
He was also unsuccessful in the 1849 election for associate justice of the Wisconsin Supreme Court.

Lynde served as Mayor of Milwaukee in 1860.
His Wisconsin political career also led him to the state legislature; he served in the Wisconsin State Assembly in 1866 and the State Senate in 1869 and 1870.
He returned to the U.S. House of Representatives in 1875, where he served two full terms this time representing Wisconsin's 4th congressional district as part of the 44th and 45th Congresses from March 4, 1875, till March 3, 1879.

Lynde died in 1885 in Milwaukee at age 68.
He is interred in Milwaukee's Forest Home Cemetery.
His wife died in 1897 and was also interred there.
Lynde was born in Sherburne, New York. He graduated from Yale College, in 1838, and Harvard Law School, in 1841, and was admitted to the bar in New York. He moved to Milwaukee, Wisconsin Territory, shortly thereafter, accompanied by his new wife, Mary.
In 1842 he founded the law firm, Finch & Lynde, with his partner Asahel Finch, Jr. Finch & Lynde survives today as Foley & Lardner, one of the oldest and largest law firms in the country.
Lynde became Attorney General of the Wisconsin Territory in 1844 and United States Attorney for Wisconsin in 1845. He also served as president of the board of trustees of the Village of Milwaukee.
When Wisconsin was admitted as a state in 1848, Lynde was elected as a Democrat to the United States House of Representatives, one of Wisconsin's first two representatives. He joined part of the 30th United States Congress from June 5, 1848, till March 3, 1849, representing Wisconsin's 1st congressional district. He lost his reelection bid for the 31st Congress. He was also unsuccessful in the 1849 election for associate justice of the Wisconsin Supreme Court.
Lynde served as Mayor of Milwaukee in 1860. His Wisconsin political career also led him to the state legislature; he served in the Wisconsin State Assembly in 1866 and the State Senate in 1869 and 1870. He returned to the U.S. House of Representatives in 1875, where he served two full terms this time representing Wisconsin's 4th congressional district as part of the 44th and 45th Congresses from March 4, 1875, till March 3, 1879.
Lynde died in 1885 in Milwaukee at age 68. He is interred in Milwaukee's Forest Home Cemetery. His wife died in 1897 and was also interred there.
William Pitt Lynde