After moving to Arizona he worked in various occupations, as waiter, milkman, bellhop, and publicity agent for the Southern Pacific Railroad.

With the outbreak of World War I in 1914, Martensen went to Canada and joined the Canadian Army.

[1][2][3] In 1928, he won the Republican primary for the State Senate from Pinal County in a write-in vote campaign.

The results were challenged by Perry, but the courts finally adjudicated Martensen as the winner.

[2][5] Martensen was killed at age 54 in a car accident on December 5, 1948, while visiting San Bernardino County, California.