And maybe those events, while bad and scandalous did not reach the level of Impeachement.
However, Clinton did get impeached for lying under oath.
Lincoln did not.
I am sorry that you do not like the way checks and balances work in our country, but if Lincoln were the tyrant that you think he was, impeachment would have been the responsibility of the Congress, just as it was when Clinton was impeached.
As for Nixon, he was forced out to avoid impeachement.
...or perhaps they did but the congress at the time simply lacked the backbone or partisan makeup to carry through with it much like the US Senate lacked the backbone to convict Clinton. Congress is a fundamentally political institution and, being one, they can and do opt for lesser but nevertheless certain expressions of disapproval than the extremely rare act of impeachment.
However, Clinton did get impeached for lying under oath.
Clinton got impeached on two counts - perjury and obstruction of justice.
Lincoln did not.
I don't believe Lincoln ever testified before a court on one of the many cases involving him thus the occasion for perjury would not arise. He did indeed obstruct justice though to the point of using military officers to harrass sitting judges, unconstitutionally suspending their salaries, and impeding their rulings from being carried out and their membership from meeting. Lincoln's obstruction of justice in those regards actually exceed Clinton's in severity.
As best as I can tell, they enjoy the benefits of being Americans, while hating the country and longing for an independent south.