Berry served in the House of Representatives of the South Dakota Legislature from 1925 to 1931, and was a member of the Custer State Park Board.

Elected governor twice, in 1932 and 1934,[3] Berry assisted in South Dakota's recovery from the Great Depression.

He called the legislature into special session to legalize 3.2 percent beer and again to enact unemployment insurance.

[5] In 1938, he defeated interim United States Senator Herbert Hitchcock in the Democratic primary,[6] but lost the general election to Chan Gurney.

[7] In 1942, Berry defeated incumbent United States Senator William J. Bulow in the Democratic primary[8] but lost the general election to Harlan J.