Thread tl;dr
Catholicism is the original form of Christianity. It is Ignorant protestants like you that make the world hate us Americans.
(Protestant=not Catholic)
Protestant is any christian organization spawned from the reformation side of things that reject the pope. Technically the orthodox church is far more original than the catholics. And then you have some eastern christianity that is basically what christianity was before organization.
So no, catholicism is not the original form of christianity.
Especially when you get into original sin, the immaculate conception, and things like purgatory. All were invented late in the game, yet catholics base a lot of their beliefs on things they made up themselves.