Reply #4: Only as a lowered number. The procedural filibuster is nearly as old as the Senate.

[WeDidIt]

It was first created by Thomas Jefferson in the Rules of the Senate he wrote.

Back then, it was a 2/3 requirement and was originally intended to insure all members of the Senate had time to arrive in order to cast their votes on legislation.

It didn't enter widespread use until recently because minorities rarely felt they had incentive and the power to thwart the will of the majority in the Senate. As a standard procedural tactic, it started in the nineties under Bob Dole. That use in what was considered extreme circumstances remained the same under Democrats after Bush took over. When the Democrats again took over control of the Senate, it became the standard for every piece of legislation and has remained the standard ever since.