when did the filibuster start

The filibuster in the U.S. Senate began as an occasional practice in the 19th century, with the term and more frequent use developing over time. The mechanism to end or limit debate (cloture) was first tested successfully in 1919, and the cloture threshold has changed a few times since then, most notably reducing from two-thirds to a simple majority (60 votes) in 1975 for most matters. In practice, the filibuster emerged as a tool used by minority senators to block legislation, and its importance grew in the mid-20th century as civil rights legislation and other major fronts of policy were contested. If you’d like, I can pull up precise dates and milestone events from reputable sources to provide a concise timeline.