Term of Office: 9/9/1862 to 1/5/1863
Party Notes: "Aaker was one of the first Scandinavian legislators in the state, an active Republican, and a delegate to the first convention of the party held in Wisconsin in 1856." (History of the Scandinavians and Successful Scandinavians in the United States, edited by Olof Nickolaus Nelson, 1900, p. 365-366); The St. Paul newspaper traditionally listed members who won the election with party affiliation (Democrat or Republican). In 1862 they only identified the Democrats, the assumption is that the rest were Republicans. Since he wasn't identified as a Democrat, the assumption is that he was a Republican. (St. Paul Pioneer and Democrat, January 7, 1862)
Although he was elected to the seat, it doesn't appear that he served in the regular session in 1862. He's listed as being absent for most of January in the Minnesota Journal of the House, 1862. After that he's not mentioned and doesn't appear on the roll call votes. On September 9, 1862 in the Minnesota Journal of the House on page 5 it states "Mr. Thacher moved that his colleague elect, Mr. L.K. Aaker, who was not present at the regular session, be admitted to his seat. Which was agreed to." He then took the oath of office on that day. His active duty during the United States Civil War appears to explain his absence since it coincides with this time period.