Sarcasm - kind of. We were taught that Booth acted alone, no mention of a conspiracy. Yes others were caught and hanged. There was always question as to who was behind it. One of the conspirators ended up in Europe.
But in school this is the line: John Wilkes-Booth Killed Lincoln then some mention that he was a Southerner. Done.
Oswald - good question regarding Tippit. Did witnesses see Oswald? Who knows. There is doubt that he had time to leave the book depository, kill Tippit & get to the theater in time to be found there. The bullets extracted from Tippit's body were not positively matched to Oswald's revolver.
Not saying Oswald wasn't involved somehow knowingly or not (Patsy). But he was definitely silenced before it could be conclusively proven he acted alone.
Oh, and we are always taught in school that Lee Harvey Oswald killed JFK because LHO was a communist and was upset about Cuba & the Bay of Pigs. Done.
Think about this - at the extreme height of the cold war how is it that a US Marine defects to the USSR, renounces his US citizenship, marries a Soviet citizen and then the US embassy gives him back his citizenship with repatriation money so he can return with his new Soviet bride? LHO was much more complex than the "lone nut" we have been taught to believe he was.
"One resists the invasion of armies; one does not resist the invasion of ideas" Victor Hugo