On July 4, 1776, immediately after declaring the United States independent of Great Britain, the Continental Congress established a committee to design an official seal for the new nation.  The resulting Great Seal of 1782 became a principal symbol of American sovereignty and independence.

Meeting in Philadelphia in the 1790s, members of the early Senate so admired the visually appealing Great Seal that they had it reproduced on a carpet woven for their chamber.  They also selected a similar design for the first official Senate seal.

The earliest surviving impression from the first Senate seal appears on a 1798 impeachment trial summons.  It displays a German imperial eagle, with a shield at its breast, its talons clutching arrows and an olive branch.  Rays of light burst from clouds above the eagle, symbolizing the emergence of the new nation.  

In 1830, the Senate commissioned a replacement seal.  Following the then-popular neoclassical style, that device featured three goddesses symbolizing justice, liberty, and strength.  A chain of twenty-four links, representing the existing number of states, formed an encircling border.  That second seal appears among the official documents of President Andrew Johnson’s 1868 impeachment trial.

The nation’s 1876 centennial renewed interest in such national symbols and prompted a redesign of the Great Seal.  On March 31, 1885, the Senate took notice of that redesign and ordered an updating of its own.  Heavily used during an 1876 impeachment trial, the old seal had been left in poor condition in a Capitol basement.  As the Senate approached its one-hundredth anniversary, it paid a Philadelphia engraver $35 to design a third version featuring a liberty cap above a central shield, emblazoned with thirteen stars and an equal number of vertical stripes.

Today, that seal—first used in 1886—remains in the custody of the Secretary of the Senate.  Measuring one-and-a-half inches in diameter, it is used on impeachment and treaty documents, and on presentation copies of Senate resolutions recognizing appointments, commendations, and notable achievements.

In the mid 1980s, designers of the Senate’s first official flag debated which color best symbolizes the Senate: dark blue or deep red.  Although they settled on blue for the flag’s background, they had no doubts about the best choice for that banner’s centerpiece: the Senate seal.  Today, this once obscure symbol of Senate power and prerogatives is now easily visible in every senator’s office and above the dais of the Hart Building’s central hearing room.