While Willson was in the region, settlers began to look at establishing a government in the unorganized area. These led to the holding of several meetings in 1841 and again in 1843. During the May 2, 1843,
Champoeg Meeting, Willson served as secretary, and voted in favor of creating a provisional government, which passed with a 52-50 vote. In 1844, he was wounded in the
Cockstock Incident. In 1845, he was elected as the president of the bench in the
Champoeg District. During the
Cayuse War of 1847 to 1850 he was appointed to the commission that worked to raise the money to fight the war that was born out of the
Whitman Massacre. Willson participated in the Oregon Exchange Company in 1849 that minted the
Beaver Coins prior to the arrival of U.S. authority in the region. He ran for
territorial delegate to
Congress in 1851, but lost to
Joseph Lane. ==Later years==