Hilker worked in the candy wholesale business, as a coal broker, and in sales promotion.

He was a member of the United Spanish War Veterans, the Fraternal Order of Eagles, and the Knights of Pythias.

Hilker remained active in politics and was a delegate to the 1936 Republican National Convention.

In 1940, he reclaimed his former Assembly seat, defeating incumbent Wisconsin Progressive assemblyman Jack Harvey.

It was attended by many Wisconsin legislators, including pallbearers senators Bernhard Gettelman, Chester Dempsey, J. Earl Leverich, Taylor G. Brown, and Everett F. LaFond, and assemblyman Fred Pfennig.