Senators were elected over a wide range of time throughout 1912 and 1913, and a seat may have been filled months late or remained vacant due to legislative deadlock.

Democratic Governor of Arkansas Joseph T. Robinson appointed John N. Heiskell January 6, 1913, to continue the term just until a special election.

On January 29, 1913, the Arkansas Legislature elected Democratic businessman and former judge William Marmaduke Kavanaugh just to finish the term that would end in March 1913.

For the initial senators there was a popular vote held December 12, 1911 — before statehood — and the newly formed state legislature effectively ratified the popular votes March 26, 1912: Democrat Henry F. Ashurst (class 1) and Democrat Marcus A. Smith (class 3).

[27] During the convention, he positioned himself for a U.S. Senate seat by avoiding the political fighting over various clauses in the constitution which damaged his rivals.

Democrat Charles J. Hughes Jr. (D) had died January 11, 1911, and the seat remained vacant for two years because the Colorado General Assembly failed to elect a successor.

[5] In the 1912 state elections, Democrat Charles S. Thomas (former Governor of Colorado) won the popular vote [citation needed].

Democratic lawyer and former-Judge Kirtland I. Perky was appointed November 18, 1912, to continue the term pending a special election.

Five-term incumbent Republican William P. Frye had died August 8, 1911, and Democrat Obadiah Gardner was appointed September 23, 1911, to continue the term, pending a special election.

The Minnesota Legislature unanimously ratified the popular vote January 21, 1913: Nelson later would be re-elected again in 1918 to a fifth term, before his 1923 death.

Percy had advocated education for blacks and worked to improve race relations by appealing to the planters' sense of noblesse oblige.

Disenfranchisement of blacks made the Democratic primary the deciding competitive race for state and local offices in Mississippi.

In this rematch, Vardaman's campaign was managed by Lieutenant Governor of Mississippi (and future senator) Theodore Bilbo, who emphasized class tensions and racial segregation, attacking Percy as a representative of the aristocracy of the state and for taking a progressive stance on race relations.

Vardaman, however, would only serve one term, losing renomination in 1918, primarily due to his vote against entry into World War I. One-term Republican Joseph M. Dixon ran for re-election as a Progressive, but lost to Democrat Thomas J. Walsh.

Despite the Democratic majority, the Nebraska legislature elected Republican Norris unanimously, upholding the popular vote.

Although Congressman Norris, a Progressive Republican, has won the preference vote, returns indicate that a Democratic legislature has been elected.

Republican former-judge William A. Massey was appointed July 1, 1912, to continue the term that would end in 1917, pending a special election.

The New Hampshire legislature failed to elect a new senator after 42 votes, so the March 4, 1913, term begin with the seat vacant.

Finally, on March 26, 1913, on the 43rd vote, Democrat Henry F. Hollis was elected with the required majority, albeit slight.

One-term incumbent Republican Frank O. Briggs lost re-election to Democratic state judge (and former member of the U.S. House) William Hughes.

[62][12] Owen would run for U.S. president (failing to achieve his party's nomination), and then serve a third and final term as the young state's initial Class 2 senator, retiring in 1925.

[63] Intent on proving himself a man of the people, Harry Lane set what might be a record for campaign frugality in his victorious effort, with his entire race run for $75 plus travel expenses.

When asked concerning his ideas on national issues Judge Colt replied that he was still a member of the court, and until his resignation he did not think it would be dignified or courteous to talk upon the subject.

He had long avoided any opposition because of his influence in the Democratic Party in the state, but by 1912 he had moderated his positions and lost the radical edge that had allowed him to build up a hard core following of support.

The radicals in the state electorate had thrown their support to Coleman Livingston Blease in the gubernatorial election of 1910 and the Bleasites were determined to knock his chief opponent, Tillman, out of office.

The voters of the state split their support between the Tillmanite and Bleasite factions as both Tillman and Blease won their respective primaries.

Chief Justice Of The Tennessee Supreme Court John K. Shields was elected January 23, 1913, to the next term beginning March 4, 1913.

[78] Democrat John W. Daniel died June 29, 1910, and Democrat Claude A. Swanson, a former Governor of Virginia and former Congressman, was appointed August 1, 1910, to finish the term ending March 1911 and again appointed February 28, 1911, to begin the 1911–1917 term, pending a special election.

[80][81] Democrat Clarence Watson had been elected in 1911 to finish a vacant term, but he lost re-election February 21, 1913, to Republican federal judge Nathan Goff Jr. after multiple deadlocked ballots.

He would only serve the one term, retiring in 1919 due to ill-health and having barely cast any roll call votes throughout his Senate career.