Andrew Johnson and William Clinton were the two that were impeached.
An Impeachment procedure against a federal government official can only be made by the House of Representatives and so it was with Clinton,
Andrew Johnson
President Gerald Ford had two attempts made on his life, he escaped both times.
There were no recorded assassination attempts made against President Van Buren.
Fidel Castro has had the most assassination attempts against him. 638 times by the CIA.
He made 36 attempts, against Toronto on 3/20/2005.
The term is impeachment. The US House of Representatives investigates charges against the President to determine if he has committed an impeachable offense. If a bill of impeachment is approved by 2/3 of the House, the President is impeached, or accused. He is then tried by the US Senate, and if voted guilty by 2/3 of the senators, he is removed from office. Two Presidents have been impeached (Andrew Johnson and Bill Clinton) but neither was convicted and removed.
He resigned before they could take him to court.
In the U.S. Constitution, impeachment is like being accused; impeachment is the job of the House of Representatives. Once the person has been impeached - accused of a crime - then the case goes to trial. The House carries out the trial, and the Senate acts as the jury. Impeachment is very rare; only a few judges have ever been removed from office, and while two Presidents have been impeached, neither was removed from office. Removal from office is the ONLY penalty that the Senate can impose. If removed from office through impeachment, the person can never again hold any office of ANY kind for the government of the United States.
The Ohio State Buckeyes made 14 straight 3 pointers collectively as a team against Wisconsin on 3\6/11. They hit 14 of 15 attempts which is also the highest % of 3 pointers made in NCAA history(min 10 attempts)
Successful assassinations were made of:Abraham LincolnJames GarfieldWilliam McKinleyJohn KennedyUnsuccessful attempts were made on:Andrew JacksonAbraham Lincoln (while President-elect)Theodore Roosevelt (after leaving office)Franklin Roosevelt (while President-elect; some believe he was not actually the target)Harry TrumanJohn Kennedy (while President-elect)Richard NixonGerald Ford (two attempts)Jimmy CarterRonald ReaganGeorge H. W. Bush (after leaving office)Bill ClintonGeorge W. Bush (several attempts)Batack Obama (several planned attempts)
As per other internet sources there is no limit on number of attempts and age.