A Republican from the Eleventh District, the fifty-five year old lawyer lived in North Yakima. Born in Pennsylvania in 1834, Prosser had been a teacher, surveyor and miner. He was a colonel in the Civil War. In 1886 he became auditor of Yakima county, and he was special land agent for the general land office for Washington and Oregon. Prosser served on the following committees: Military Affairs, chairman; Apportionment and Representation; Harbors, Rivers, Tidewaters and Navigable Streams; rules for Convention.

(March 16, 1834 — September 23, 1911) Prosser was a teacher, businessman, and politician. William Farrand Prosser was born in Williamsport, Pennsylvania in 1834 and moved to Tennessee after the Civil War. While a child, Prosser received limited school but became educated enough to become a teacher. He studied law but never practiced. In 1854, Prosser moved to California and became a miner. During the Civil War, he enlisted in the Union Army and attained the rank of colonel. After the war, he settled in Nashville, Tennessee and became a farmer. Prosser served in the State House of Representatives (1867-1869). He was elected as a Republican to the United States House of Representatives an served from March 4, 1869 to March 3, 1871. After serving in Congress, Prosser worked as a publisher and was the director of the Tennessee, Endgefield and Kentucky Railroad. In 1879 he was appointed by President Hayes to the Interior Department for Oregon, Washington, and Idaho. He was a delegate to the first State constitutional convention of Washington. [Source: “Biographical Directory of the United States Congress, 1774 - Present,” available at https://bioguide.congress.gov/search/bio/P000550]