Boardman served as clerk of the state senate in 1820.
His first major position was as a Judge of Probate in New Haven, Connecticut from 1825 to 1829.
He was a Connecticut state senator in the fourth district from 1830 to 1832.
 
A member of the Connecticut state house of representatives from 1836 to 1839, in 1845, and from 1849 to 1851, he served as Speaker of the Connecticut State House of Representatives in 1836, 1839, and 1845.

Boardman was a delegate to Whig National Convention from Connecticut in 1839 and was a member of the Balloting Committee, and served as speaker.
He was chosen as a Whig to the Twenty-sixth Congress to fill the vacancy caused by the resignation of William L. Storrs; reelected to the Twenty-seventh Congress and served from December 7, 1840, to March 3, 1843.
 He was chairman of the Committee on Public Buildings and Grounds during the Twenty-seventh Congress.
 
As a member of the Governor's Foot Guard, Boardman rose to the rank of major.
In 1864, he was member of the Common Council of New Haven City.
He was a trustee of Trinity College from 1832 until 1871 and acted as the president of both the Gas Light Company of New Haven and the New Haven Water Company.
He was member of the Episcopal Church and held offices among which were: Warden  and vestryman of Trinity Church on the Green, New Haven; trustee of the General, Theological Seminary of the Protestant Episcopal Church; Trustee of the Cheshire Academy; President of the Board of Bishops' Fund.
He was a founder and Vice President of the General Hospital Society of New Haven (now called Yale New Haven Hospital).
On July 28, 1857, he married Lucy Hall of Poland, Ohio.
He and his wife had no children.
Boardman served as clerk of the state senate in 1820. His first major position was as a Judge of Probate in New Haven, Connecticut from 1825 to 1829. He was a Connecticut state senator in the fourth district from 1830 to 1832.  
A member of the Connecticut state house of representatives from 1836 to 1839, in 1845, and from 1849 to 1851, he served as Speaker of the Connecticut State House of Representatives in 1836, 1839, and 1845.
Boardman was a delegate to Whig National Convention from Connecticut in 1839 and was a member of the Balloting Committee, and served as speaker. He was chosen as a Whig to the Twenty-sixth Congress to fill the vacancy caused by the resignation of William L. Storrs; reelected to the Twenty-seventh Congress and served from December 7, 1840, to March 3, 1843.  He was chairman of the Committee on Public Buildings and Grounds during the Twenty-seventh Congress.  
As a member of the Governor's Foot Guard, Boardman rose to the rank of major. In 1864, he was member of the Common Council of New Haven City. He was a trustee of Trinity College from 1832 until 1871 and acted as the president of both the Gas Light Company of New Haven and the New Haven Water Company. He was member of the Episcopal Church and held offices among which were: Warden  and vestryman of Trinity Church on the Green, New Haven; trustee of the General, Theological Seminary of the Protestant Episcopal Church; Trustee of the Cheshire Academy; President of the Board of Bishops' Fund. He was a founder and Vice President of the General Hospital Society of New Haven (now called Yale New Haven Hospital). On July 28, 1857, he married Lucy Hall of Poland, Ohio. He and his wife had no children.
William Whiting Boardman