Timothy O. Howe's term as U.S. Senator began (he was elected for a six-year term from this date).

The evidence

• “The successful candidate was Timothy O. Howe, republican, who was elected for a full term of six years from the 4th of March, 1861. One of the important acts passed at this session of the legislature apportioned the State into senate and assembly districts, by which the whole number of members in both houses was increased from one hundred and twenty-seven to one hundred and thirty-three.”

  1879-history-of-rock-county/02-wisconsin-as-a-state.md, PDF p. 64

  Butterfield, C. W., et al. The History of Rock County, Wisconsin: its early settlement, growth, development, resources, etc. Chicago: Western Historical Company, 1879. Cornell University Library via the Internet Archive, archive.org/details/cu31924028871585.

  Grade A: Found on a page of one of our sources