These elections occurred in the middle of Democratic President Woodrow Wilson's first term.

This was also the first of three times in American history that the opposition party failed to flip any Senate seats, along with 1934 and 2022.

One Democrat died on August 8, 1913, and his seat remained vacant until a May 11, 1914 special election.

Nineteen races had a margin of victory under 10%: Democrat Joseph F. Johnston died August 8, 1913.

Although he easily defeated his primary challenger, he faced a large field of candidates in the general election.

There were two elections due to the February 14, 1914, death of Democrat Augustus Octavius Bacon.

Democrat Thomas W. Hardwick was elected November 3, 1914, to finish the term that would end in 1919 and served until losing renomination in 1918.

The Republican nominee was Augustus E. Willson, who flipped the seat in 1907 after Beckham's term ended.

[38] Initially, Harding was not interested in running for U.S. Senate, due to the divisive remnants of the 1912 elections between the conservative and progressive factions of the Republican party.

Harry Daugherty, an Ohio political boss, was interested in running for the seat himself upon learning of incumbent Senator Theodore Burton's plans to retire upon the expiration of his term, but party leaders advised him not to run.

Instead, Daugherty unsuccessfully attempted to stage a draft movement to convince Harding to run for the seat.

After the death of Amos Kling, the father of Harding's wife Florence, she encouraged her husband to run.

Retiring Senator Theodore Burton also claimed credit, saying to his biographer that Daugherty did not agree to throw his support behind Harding until after learning he had backed him.

Rather than antagonizing his opponents, Harding notably tried to keep and make friends within the Republican party, to the frustration of those running against him.

[39] In the general election campaign, Harding faced Democratic nominee Timothy Hogan and Progressive candidate Arthur Garford.