No, Desh, no.
Even later September 22, 1789, incident described in Senator William Maclay's diary does not qualify as a filibuster in the modern or historical sense of the term, despite the U.S. Senate's official historical overview referencing it as an early appearance of the underlying tactic of using extended speeches to delay legislation.
The Senate's description states: "The tactic of using long speeches to delay action on legislation appeared in the very first session of the Senate. On September 22, 1789, Pennsylvania Senator William Maclay wrote in his diary that the 'design of the Virginians . . . was to talk away the time, so that we could not get the bill passed.'"
This was during a debate on a bill to temporarily locate the federal capital in Philadelphia, where Virginia and South Carolina senators prolonged discussion to favor a southern site like Georgetown—yet the bill passed later that day by a 12-7 vote, with no record of the delay extending beyond the session or requiring extraordinary measures to overcome.
Historians and the Senate itself distinguish this from a true filibuster for several reasons: the term "filibuster" did not enter U.S. legislative lexicon until the 1850s (derived from Dutch/Spanish words for "pirate," evoking obstructionist "raiders"); no formal Senate rules explicitly recognized or regulated such tactics until the 1806 elimination of the "previous question" motion (which had allowed debate closure); and the first widely acknowledged filibuster occurred in 1837, when Whig senators obstructed for three weeks to prevent expunging a censure of President Andrew Jackson.
Earlier instances like 1789 are better viewed as proto-filibusters—incipient uses of unlimited debate under rules inherited from the Continental Congress—but not the fully obstructive strategy that later defined the practice.
