At New York City's Federal Hall (pictured), on March 4, 1789, the Senate convened for the first time. From 1789 until 1933, when the Constitution's Twentieth Amendment changed the convening time to 12 noon on January 3, the date of March 4 would rank among the most important on the congressional calendar.
As the Constitution's framers had no way of knowing when the new constitution would be approved, they directed the Congress under the expiring Articles of Confederation to set the convening date. In September 1788, once the necessary nine states had ratified, the Confederation Congress chose March 4.
In the years that followed 1789, March 4 became most significant as an ending date. Although the Senate customarily convened on the Fourth of March every four years for a few days to consider nominations of new presidential administrations, the Senate and the House would not again come together on March 4 until 1867. While Congress followed the constitutional requirement to convene annually on the first Monday in December, it almost always adjourned its final session on March 4.
As early-nineteenth-century members approached a final session's crucial closing minutes, they regularly questioned whether the Congress expired at midnight on March 3, or noon on March 4. Surprisingly, this fundamental point remained unsettled for decades. Finally, at midnight on March 3, 1851, Mississippi Senator Jefferson Davis declared that his term had expired and refused to vote when further roll calls were ordered. This sparked a discussion of the difference between a natural day, beginning at midnight, and a "political" day, starting at noon. The Senate then adopted a resolution stating its opinion that, as the Senate customarily convened at noon on March 4, the previous Congress must end at that time.
Whether at midnight or noon, the Senate often gained extra time for last-minute appropriations bills by sending a doorkeeper, pole in hand, to gently move the chamber clock's minute hand from natural time to "political" time.