They always start at 1837, when it was first used.
They also (and this is SO key), never get into the fundamental fact that the framers NEVER considered the Senate to be a place where a minority could literally stop legislation dead in its tracks permanently (for that session).
Manchin is simply wrong (as are the Rethugs and any other defender of the filibuster) when he says the Senate was designed that way since 1789. It was ALWAYS envisioned from the beginning as a majoritarian body, the same as the House. It just was designed for lengthier debate.
Until it is massively altered via new precedents (using Senate Rule Rule XX, so as to render it completely toothless) or removed as a Rule (removed is never going to happen, it takes a 2/3rds majority) it is, along with the Electoral College, the ability of the States to run FEDERAL elections, gerrymandering, and yes, the very way the Senate itself is structured (soon 70% of the seats will be controlled by just 30% of the population, and that 30% is far more reactionary, white, less educated, fundie religious, racist, older on average, and RW than the other 70% of the population) a long wave Constitutional ticking time bomb, that when combined with the other things listed, quite likely will lead eventually to the dissolution of the Union of The States.