William M. Jack

In 1922 he unsuccessfully ran for justice of the peace in Lusk. In 1924 he successful ran for one of Niobrara County's two seats in the state house and was reelected in 1926.[4] In 1928 he moved to Casper after being transferred by an oil company and was elected to the state house again in 1930 and reelected in 1932. In 1933 he was elected as Speaker of the House becoming the first Democratic Speaker in Wyoming's history.

On March 30, 1934 he announced that he would run for the Democratic nomination for state auditor and defeated incumbent Auditor Roscoe Alcorn in the general election in the Democratic landslide of the year when they took control of all five statewide offices and the state legislature.[5] In early 1934 Governor Leslie A. Miller had to temporarily leave Wyoming resulting in Secretary of State Lester C. Hunt becoming acting governor and further responsibility out of state lead to Senate President Nels H. Smith becoming acting governor and on March 5, 1934 Jack became acting governor for a few hours.[6] When the gas chamber in the Wyoming State Penitentiary was under construction Jack stated that he was against it and supported efforts to prevent its completion along with members of the state legislature, but it was eventually completed.[7]

On April 2, 1938 he announced that he would seek reelection and after facing no opposition in the primary defeated C. J. Rogers in the general election. In the 1938 elections the Democrats lost three statewide elections and control of the state legislature, but Jack was the best performing statewide candidate.[8][9] In 1940 he served as the chairman of the Natrona county delegation to the Wyoming Democratic party's state convention and was later named as temporary chairman.[10]

On May 12, 1942 he announced that he would seek reelection to a third term and easily won the primary against Carl A. Johnson and later won in the general election against Everett T. Copenhaver.[11][12]

In 1944 Secretary of State Mart T. Christensen died and after Governor Lester C. Hunt rejected Deputy Secretary of State Everett T. Copenhaver for the position he chose to appoint Jack. On October 16, 1944 he resigned as auditor to take up the position of secretary of state.[13] On January 10,1946 he announced that he would not seek a term in his own right or seek any other political office.[14]