Hagaman served in the 117th Kansas Ammunition Train during World War I and received a Purple Heart with a special citation.

Hagaman was elected to be the Johnson County representative to the state legislature, first in 1939, and was re-elected twice more.

In an unprecedented move, Governor Hagaman invited Governor-elect Edward Arn to budget hearings.

[1]After losing the bid for Republican Party nomination as governor, Hagaman returned to his law practice in Fairway, Kansas.

Hagaman died in a hospital in Kansas City on June 23, 1966, and is buried at Fairmount Cemetery in Denver, Colorado.