He remained with the regiment as it moved south until 1862, when he was transferred to an overland expedition under Captain Medorem Crawford to assist emigrants to Oregon.

[2] In June 1867, mayor Thomas J. Holmes, who had been appointed the previous year after the resignation of Henry Failing, was elected to a full term, and then died the following morning.

[4] Judge Aaron E. Waite was first chosen by the City Council to replace Holmes, but declined due to ill health.

[5][6] Chapman was appointed mayor on July 31, 1867,[7][8] and served until the following June, when a special election to complete Holmes' term was won by Hamilton Boyd.

Chapman defeated Failing, who had been criticized for a number of his ordinances and his response to a massive 1872 fire that consumed 22 blocks of the Portland waterfront.