Idaho was admitted as the 43rd state in the Union.
George Laird Shoup, born in Kittanning, Pennsylvania, but later of Salmon City and Boise, and William John McConnell of Moscow, Idaho, were elected as Idaho's first United States senators. Shoup was elected while serving as the state's first governor and signed the credentials certifying his own election as senator.
Idaho’s new senators drew lots to determine their Senate class assignments. William McConnell drew Class 3, with a term due to expire in just two months, on March 3, 1891, and George Shoup drew Class 2, with a term to expire on March 3, 1895.
Born in Palestine, Illinois, but later of Blackfoot, Idaho, Fred Thomas Dubois began his service as the state’s Class 3 senator. Dubois had been elected by the state legislature in December 1890 for the six-year term beginning March 4, 1891, but William H. Clagett, who was elected in February 1891 by a second vote of the legislature, challenged Dubois’s election when the latter presented his credentials to the Senate in December 1891. On March 3, 1892, the Senate voted that Dubois should retain his seat. Although defeated for reelection in 1896, Dubois would serve again in 1901 as a Class 2 senator.
George L. Shoup became chairman of the Senate Committee on Education and Labor (today's Committee on Health, Education, Labor, and Pensions), serving until 1897.
Former senator Fred T. Dubois took his oath as a Class 2 senator. After one Senate term as a Republican (1891‑1897), Dubois led Idaho's Silver Republicans into an alliance with the Democrats and soon became a rising figure in the Democratic Party. Dubois won election to the Senate in 1900 as a Silver Republican, but officially changed to a Democrat before taking his seat.
Originally of Fairfield, Illinois, William Edgar Borah of Boise, Idaho, began the first of six Senate terms. During his 32 years and 10 months in the Senate, a record for Idaho's senators, Borah played a leading role in securing passage of constitutional amendments for a graduated income tax and the direct election of senators. As a leader of the Senate's "Irreconcilables," Borah was instrumental in blocking the United States from joining League of Nations with the rejection of the Treaty of Versailles.
William E. Borah became chairman of the Senate Committee on Education and Labor (today's Committee on Health, Education, Labor, and Pensions), serving until 1913. Borah headed the committee again from 1922 to 1924.
Incumbent senator James Henry Brady of Pocatello became Idaho's first directly elected senator under the terms of the Seventeenth Amendment, passed in 1913. Brady was first elected to the Senate in 1912 to fill the vacancy caused by the death of Weldon B. Heyburn, whose term ended March 3, 1915.
William E. Borah became chairman of a select committee that investigated and exonerated Montana senator Burton K. Wheeler from charges that he illegally acted as an attorney in cases in which the United States was a party.
William E. Borah ran unsuccessfully as candidate for the Republican presidential nomination in 1936, but in November he was elected to his sixth term in the Senate.
A funeral service for William E. Borah was held in the Senate Chamber. Among those in attendance were senators, several hundred House members, the Supreme Court, the cabinet, diplomats, and President Franklin Roosevelt. A congressional delegation that included ten senators also traveled to Idaho for Borah's burial service.
Born in Portland, Oregon, but later of Pocatello, Idaho, Glen Hearst Taylor was nominated for vice president of the United States on the Progressive Party ticket, headed by former vice president Henry A. Wallace of Iowa. The ticket was defeated in November's general election and Taylor's single term in the Senate ended January 3, 1951.
Frank F. Church became chairman of the Select Committee to Study Governmental Operations With Respect to Intelligence Activities, serving until 1976. The "Church Committee," which investigated CIA and FBI operations, was terminated on May 19, 1976, when it was replaced by the Senate Select Committee on Intelligence.
Idaho-born Gregory S. Casey of Boise was elected Senate sergeant at arms and served until his resignation on November 9, 1998.
The Senate Select Committee on Ethics issued a public letter of admonition to Larry Craig for his "conduct in connection with [his] June 11, 2007, arrest at the Minneapolis‑St. Paul International Airport and [his] August 2007 guilty plea in the State of Minnesota, County of Hennepin, Fourth Judicial District, and [his] conduct related and subsequent thereto." The committee said that the "conduct to which [he] pled guilty, together with [his] related and subsequent conduct . . . constitutes improper conduct reflecting discreditably on the Senate."