He was admitted to the bar, and joined the practice of Harvey Boutwell, a blind attorney whose need to have papers read aloud furthered Dever's oratorical skills.

Among his claimed successes were a 95% conviction rate, and the closure of a significant number of lenders engaging in usurious lending practices.

He also identified under- or mis-utilized trust funds, including one which was eventually used for construction of the Hatch Shell on Boston's Charles River Esplanade.

He was subsequently commissioned a lieutenant commander, and served in the North Atlantic, European and African Sectors until his discharge at the end of the war in 1945.

Assignments included command of the Marine Corps contingent at Argentia, Newfoundland and Labrador, and the delivery of election ballots to military posts.

During his tenure, Dever increased state aid to schools and issued an executive order to extend higher education benefits to Korean War veterans.

He supported legislation requiring school teachers to take loyalty oaths, and he advocated increasing old age and workers compensation insurance.

The first bond issue for this work was passed early in his term; it had previously been rejected by the Democratic legislature in Bradford's tenure.

[7] Another major initiative undertaken during Dever's period in office was a significant expansion of the state's facilities for the mentally handicapped, which had suffered for many years from overcrowding and understaffing.

Dever had built a strong political machine in Massachusetts, and was widely considered a potential candidate for the United States Senate in 1952, which was also sought by John F. Kennedy.

Kennedy maintained a distance from Dever and his campaign, and was able to capture the Senate seat in the election, which was otherwise a major victory for Republicans.