After settling in Portland, he helped to found The Oregonian newspaper and promoted economic interests in the city.

He also was involved with building Canyon Road near Portland, and fought in the Rogue River War in Oregon.

Chapman Square, a park in downtown Portland, is named for him and was built on land he sold to the city.

[2] They moved to Macomb, Illinois in 1833, then to what is now Burlington, Iowa (then part of Michigan Territory) in 1835, where they were among the first settlers.

Chapman was elected as Iowa Territory's first non-voting delegate to the United States House of Representatives.

[4] After his term expired, Chapman returned to Iowa, relocating in 1843 to Agency City in Wapello County.

At this time the region was under the jurisdiction of the United States after the settling of the Oregon boundary dispute with Great Britain the previous year.

[1] He accompanied Joseph Lane, the newly appointed governor of the territory, on his return trip to Oregon.

[5] After the legislature finished its session, he moved to Oregon City and then Portland, both downstream of Salem on the Willamette River.

[2] Later in 1849, he took a trip to San Francisco, California, where he recruited Thomas J. Dryer to move to Portland and start a newspaper.

[2] Chapman purchased land in Portland from Stephen Coffin and Daniel H. Lownsdale in 1850, which he then cleared and built a home.

[2] He served as a lieutenant colonel in the militia during the Rogue River War that was fought from 1855 to 1856 against the Native Americans in Southern Oregon.

[1] He left this federal government position due to his opposition to the election of Abraham Lincoln as U.S.

[7] While in the legislature, he worked to get a $30,000 government subsidy to purchase and operate a large steam tugboat at the mouth of the Columbia River.

[9] The monument also contains two howitzers, donated by Henry E. Dosch, which he found buried in the beach near Fort Sumter.