Like its counterpart, the Senate was established by the United States Constitution and convened for its first meeting on March 4, 1789 at Federal Hall in New York City.

The history of the institution begins prior to that date, at the 1787 Constitutional Convention, in James Madison's Virginia Plan, which proposed a bicameral national legislature, and in the controversial Connecticut Compromise, a 5–4 vote that gave small-population states disproportionate power in the Senate.

On the final vote, the five states in favor of equal apportionment in the Senate—Connecticut, North Carolina, Maryland, New Jersey, and Delaware—only represented one-third of the nation's population.

Convention delegate James Wilson wrote "Our Constituents, had they voted as their representatives did, would have stood as 2/3 against equality, and 1/3 only in favor of it".

[6] One reason a couple large states voted for the Connecticut Compromise was a fear that the small states would either refuse to join the Union, or, as Gunning Bedford Jr. of Delaware threatened, "the small ones w[ould] find some foreign ally of more honor and good faith, who will take them by the hand and do them justice".

[7] Senate historian Daniel Wirls cites the poor writing of the main alternative, the Virginia Plan, as contributing to its failure.

62, James Madison, the "Father of the Constitution," openly admitted that the equal suffrage in the Senate was a compromise, a "lesser evil," and not born out of any political theory.

A proposal from the Pennsylvania delegates for each state to elect three senators was discussed, but the resulting greater size was deemed a disadvantage.

[9] The Senate originally met, virtually in secret, on the second floor of Federal Hall in New York City in a room that allowed no spectators.

Alexander Hamilton's Bank of the United States and Assumption Bill (he was then Treasury Secretary), both of which were controversial, easily passed the Senate, only to meet opposition from the House.

Backed by public opinion and President Jefferson, in 1804, the House voted to impeach Supreme Court Justice Samuel Chase, 73–32.

At the conclusion of the trial Burr said: This House is a sanctuary; a citadel of law, of order, and of liberty; and it is here–in this exalted refuge; here if anywhere, will resistance be made to the storms of political phrensy and the silent arts of corruption.

John C. Calhoun, Daniel Webster, Thomas Hart Benton, Stephen A. Douglas, and Henry Clay overshadowed several presidents.

Sir Henry Maine called the Senate "the only thoroughly successful institution which has been established since the tide of modern democracy began to run."

In an age of unparalleled industrial expansion, entrepreneurs had the prestige previously reserved to victorious generals, and many were elected to the Senate.

[12] In 1890–1910 a handful of Republicans controlled the chamber, led by Nelson Aldrich (Rhode Island), Orville H. Platt (Connecticut), John Coit Spooner (Wisconsin), William Boyd Allison (Iowa), along with national party leader Mark Hanna (Ohio).

Aldrich designed all the major tax and tariff laws of the early 20th century, including the Federal reserve system.

As chair of the Indian Affairs Committee, he pushed for the controversial policy of cultural assimilation for Native Americans, and authored laws that limited tribal sovereignty.

Before this time, a Senate leader was usually a committee chairman, or a person of great eloquence, seniority, or wealth, such as Daniel Webster and Nelson Aldrich.

However, despite this new, formal leadership structure, the Senate leader initially had virtually no power, other than priority of recognition from the presiding officer.

Robinson switched his own position on a drought relief program for farmers when Hoover made a proposal for a more modest measure.

With the addition of this rule, the Senate majority leader enjoyed far greater control over the agenda of which bills to be considered on the floor.

[24] In 1966, Edward W. Brooke became the first Black person to win a popular election to the Senate, as a liberal Republican from Massachusetts.

[26] In 1992, Carol Mosely Braun became the first Black woman elected to the Senate, where she served one term as a Democrat from Illinois.