Born near Halethorpe in Baltimore County, Maryland, Benson attended preparatory schools and Lehigh University of Bethlehem, Pennsylvania in 1890. He graduated from the law department of University of Baltimore in 1893, and was admitted to the bar the same year.
Benson served as a member of the Maryland House of Delegates from 1904 to 1910 and again in 1918, serving as Speaker of the House in 1906. He also served as a member of the Maryland State Senate from 1912 to 1914.
In 1918, Benson was elected as a Democrat to the Sixty-fifth Congress to fill the vacancy caused by the death of Joshua Frederick Cockey Talbott, and was re-elected to the Sixty-sixth Congress, serving from November 5, 1918 to March 3, 1921. He was an unsuccessful candidate for reelection in 1920 to the Sixth-seventh Congress.
After Congress, Benson resumed the practice of law in Baltimore, Maryland, and resided in Halethorpe. He was appointed the State insurance commissioner of Maryland in 1924 and served until his death in Baltimore. He is interred in Cedar Hill Cemetery of Brooklyn Station in Baltimore.