Maryland ratified the Constitution and became the seventh state to join the Union.
The Senate convened for the first time at Federal Hall in New York City. Because only eight senators were present, there were not enough to constitute a quorum. The body was forced to adjourn each day until April 6, when it achieved its first quorum of 12 members, out of the eligible 22.
Maryland's first United States senator, Charles Carroll of the Western Shore, presented his credentials and took his Senate seat.
Maryland's second United States senator, John Henry of Dorchester County, presented his credentials and took his Senate seat.
The Senate drew lots to determine the three classes of senators. Charles Carroll was assigned to Class 1 (with a two-year term to expire in 1791) and John Henry was assigned to Class 3 (with a six-year term to expire in 1795).
Senator Charles Carroll chose to resign his seat when the Maryland legislature passed a law that disqualified the members of the Maryland state senate who held seats in Congress. Carroll had served on the Maryland state senate since 1777 and he preferred to keep that position.
Senator John Henry resigned his Senate seat to begin his service as governor of Maryland. He served as governor until his death on December 16, 1798.
Senator Robert Wright of Queen Anne's County resigned from the Senate to begin his service as governor of Maryland. He served as governor until June 9, 1809.
The Senate agreed to accept Samuel Smith's credentials until he was properly elected or replaced, because the state legislature had failed to reelect him before adjourning their session.
Maryland resident Mountjoy Bayly began service as the U.S. Senate sergeant at arms. He held the post until December 9, 1833.
Robert Goodloe Harper began his tenure in the Senate and resigned in December 1816. A former resident of South Carolina, Harper had represented South Carolina in the House of Representatives from 1793 to 1800 before moving to Baltimore. After resigning his Senate seat, Harper ran unsuccessfully as the Federalist candidate for vice president of the United States.
Rockville resident Alexander Contee Hanson was appointed to fill Robert Harper's Senate seat. He was 30 years, 10 months and 6 days old on the day that he was seated. Because the minimum age for a Senator is 30, Hanson is one of the youngest senators in American history.
The Senate elected Edward Dyer as sergeant at arms and doorkeeper. Dyer served until his death on September 16, 1845.
The Senate voted to deny Eastern Shore resident Phillip F. Thomas a seat in the United States Senate. Thomas was secretary of the treasury under President James Buchanan and resigned in January 1861 at the outset of the Civil War. Many senators suspected him of partiality to the Confederate cause and believed him to be capable of disloyalty to the Union.
A congressional resolution authorized the Joint Committee on the Library to procure a bust of Chief Justice Roger B. Taney of Calvert County. The bust was completed in 1877.
Henry Jackson Ellicott, born in Anne Arundel County, completed the Senate's commission for a bust of George Mifflin Dallas for the Vice Presidential Bust Collection. The artist was a descendant of Maryland resident Andrew Ellicott, who surveyed the national capital city for George Washington in 1791.
The Joint Committee on the Library accepted Francois Regis Gignoux's painting, Niagara, The Table Rock-Winter. Colonel Charles Carroll of Carrolton obtained it shortly after its execution. Caroline Carroll, his widow, left instructions upon her death that the painting should be donated to the U.S. government. Alice Louisa Thompson, Caroline Carroll's sister, presented the painting to Congress on Carroll's behalf.
Senator Louis E. McComas of Hagerstown became chairman of the Senate Committee on Education and Labor (today's Committee on Health, Education, Labor, and Pensions), a position he held until 1905.
John Smith of Snow Hill presented his credentials to the Senate and declared that the Maryland legislature had appointed him to fill a vacancy left by the death of Senator William Whyte on March 17, 1908. Senator Julius C. Burrows (R-MI) objected, citing a statute that prevented a state legislature from filling a vacancy until the second Tuesday after notice that the vacancy existed. Nevertheless, the Senate voted to seat Smith because his election was uncontested and because Maryland's constitution required her legislature to adjourn before the next Tuesday.
In recognition of his service as secretary to Senate Sergeant at Arms Daniel M. Ransdell, the Republican Conference changed Baltimore resident E. Livingston Cornelius's title from clerk of the sergeant at arms to assistant sergeant at arms.
The Senate elected E. Livingston Cornelius to become the Senate sergeant at arms after the death of Daniel M. Ransdell on November 28, 1912. During his tenure, which ended on March 4, 1913, Cornelius supervised the inauguration of President Woodrow Wilson.
The Seventeenth Amendment to the U.S. Constitution went into effect, allowing senators to be elected by popular vote. Blair Lee, a lawyer and state senator from Montgomery County, became Maryland's first directly elected senator on November 4, 1913.
Congress authorized the Joint Committee on the Library to accept the Cumberland (Maryland) Evening and Sunday Times' gift of a bronze bust of Cordell Hull, a senator from Tennessee, executed by sculptor George Conlon of Lonaconing, Maryland.
The Foreign Relations Committee Subcommittee Investigation of Charges by Senator Joseph McCarthy, chaired by Senator Millard E. Tydings, began hearings to investigate allegations of disloyalty by State Department employees. These hearings ran until June 28, 1950. On July 7, Senator Tydings reported his committee's findings to the Senate. In a two-hour speech on the Senate floor, Tydings repudiated Senator McCarthy's charges of communists in government.
John Marshall Butler of Baltimore defeated Millard E. Tydings after Senator Joseph McCarthy entered the campaign on Butler's behalf. Tydings complained to the Rules Committee's Subcommittee on Privileges and Elections that he suspected unfair campaign practices. Upon investigation, the subcommittee denounced McCarthy's repeated acts of defamation, slander, and libel throughout the campaign but found that issue insufficient cause for unseating Butler.
Senator Herbert R. O'Conor of Baltimore became chairman of the Special Committee to Investigate Organized Crime in Interstate Commerce after Senator Estes Kefauver had chaired the committee since May 3, 1950. The committee investigated organized crime in America, and many of the hearings were broadcast nationally on TV.
Maryland resident J. Mark Trice was elected secretary of the Senate, a position he held until January 5, 1955. Trice first arrived as a Senate page in 1916, and he was depended on for his institutional knowledge of the Senate.
Former Maryland governor Spiro Agnew took the oath of office as the 39th vice president of the United States. Agnew and President Richard Nixon won reelection in 1972, but on October 10, 1973, Agnew was forced to resign after he was charged with having accepted bribes while he served as Baltimore County executive, governor of Maryland, and vice president of the United States.
Retired senator J. Glenn Beall of Frostburg, who had initiated efforts to preserve the Chesapeake and Ohio Canal during his five consecutive terms in the House and two terms in the Senate, saw his hard work rewarded when President Richard M. Nixon signed into law a bill making the canal a historic park. Beall died the following week at the age of 76.
Maryland resident William H. Wannall became the Senate sergeant at arms, a position he held until December 17, 1975.
Maryland resident Frank "Nordy" Hoffmann was sworn in as the Senate sergeant at arms, a position he held until January 4, 1981.
Paul Sarbanes of Baltimore began service in the Senate after serving in the House of Representatives from 1970 to 1977. He served for the next 30 years, until January 3, 2007, and is Maryland's longest-serving senator.
Barbara Mikulski of Baltimore was seated in the Senate after serving in the House of Representatives from 1977 to 1987, becoming Maryland's first woman senator.
Senator Paul Sarbanes of Baltimore became chairman of the Senate Committee on Banking, Housing, and Urban Affairs, a position he held until 2003.