Background
Cornelius was born in Missouri, on November 16, 1827, to Elizabeth and Benjamin Cornelius.
Cornelius was born in Missouri, on November 16, 1827, to Elizabeth and Benjamin Cornelius.
Born in Missouri, he moved to the Oregon Country with his family as a young man where he fought in the Cayuse War and Yakima Indian War against the Native Americans. He settled in Washington County near what later became Cornelius, named in his honor. A Whig and later a Republican, he served in the Oregon Territorial Legislature, and following statehood, he served in the Oregon State Senate.
In the Senate he served one term as the president of that chamber.
He also built the Cornelius Pass Road that bears his name. He was the father of Benjamin P. Cornelius, who was also prominent in state politics.
In 1845, Thomas and his family traveled over the Oregon Trail to the Oregon Country and set up a farm on the Tualatin Plains, north of what would become the community of Cornelius. After the Whitman Massacre in late 1847, Thomas volunteered for the militia of the Oregon Provisional Government in 1848.
The militia prosecuted the Cayuse War in an attempt to punish those responsible for the killings at the Whitman Mission.
After gold was discovered in California, Cornelius journeyed there for a brief time, returning to the Oregon Territory in 1849. The family would settle on 640 acres (26 km2) of their Donation Land Claim near Cornelius. In 1855, a second war against the Native Americans started east of the Cascade Mountains against the Yakima tribe.
Cornelius volunteered again for the militia.
Foreign three months he led a company with the rank of captain before being elected as colonel after James West. Nesmith resigned his commission. Cornelius continued as colonel until the end of the war in 1856.
In 1856, Cornelius was elected to upper chamber of the Oregon Territorial Legislature, called the Council. Serving as a Whig, he represented Washington, Columbia, and Multnomah counties in District 8.
In 1859, he continued holding office in the newly formed Oregon State Senate after Oregon entered the Union on February 14, 1859 as the 33rd state.
In the Oregon Senate, Cornelius continued as a Republican representing Washington County and several other counties through the 1874 legislature. His service was interrupted by the American Civil War during 1862 session, when he was authorized by President Abraham Lincoln to raise a regiment of cavalry for federal service. He was chosen as colonel of the troops and they deployed to a military post at Walla Walla, Washington, where he assumed command.
He resigned during the summer of 1862 and returned home.
During the 1866 legislature Cornelius was selected as President of the Oregon Senate. In 1872, he moved to Cornelius, which would be renamed after him, and opened a store.
In addition to the store, Cornelius owned a total of 1,500 acres (61 km2), including covering three farms, a warehouse, and a sawmill. He built the Cornelius Pass Road that linked the Tualatin Valley to the Columbia River.
Cornelius died on June 24, 1899, at the age of 71.
He was buried at the Cornelius Methodist Church Cemetery.