History19th centuryUnited Stateshigh confidence

The term 'filibuster' came into use in the 1850s to describe Senate tactics that allowed any senator to capture floor debate and prevent action on legislation.

Notes on verification

Confirmed by U.S. Senate's own historical reference materials and corroborated by multiple independent outlets (National Geographic, NPR, Fox/AP), tracing to Senate Historical Office research and Fisk/Chemerinsky (1997) study. Minor date variance (1853 vs 1863) exists across sources but doesn't undermine the 1850s framing.

Sources