Conquer Club

Both were assassinated by Southerners.
A dubious use of the term "Southerner." John Wilkes Booth was undeniably a Southern sympathizer, but he was born in Maryland, which (along with Delaware) was the northernmost of the border slave states and remained part of the Union throughout the Civil War. Additionally, Booth spent a good deal of his life in the North and "thought of himself as a Northerner who understood the South."

Oswald was nominally a Southerner by virtue of his having been born in New Orleans; he spent his youth being shuttled between Lousiana, Texas, and New York before finally joining the Marines. But Oswald's "Southerness" is of no real import, because, unlike Booth, Oswald was not motivated by a regional affiliation.

Lincoln's secretary, Kennedy, warned him not to go to Ford's Theatre.
Kennedy's secretary, Lincoln, warned him not to go to Dallas.
This is one of those coincidences that isn't a coincidence at all; it's simply wrong. John Kennedy did have a secretary named Evelyn Lincoln (who may or may not have warned him about going to Dallas), but one searches in vain to find a Lincoln secretary named Kennedy. (Lincoln's White House secretaries were John G. Nicolay and John Hay.)

John Wilkes Booth was born in 1839.
Lee Harvey Oswald was born in 1939.
Another coincidence that is no coincidence because it's plain wrong: Booth was born in 1838, not 1839.

Booth and Oswald were assassinated before their trials.
Another superficial similarity with much more significant underlying differences, and a potentially dubious use of the word "assassinated."

After Booth shot Lincoln, he fled the scene and eventually (with co-conspirator, David Herold) crossed the Potomac from Maryland into Virginia, eluding capture for a total of eleven days before federal troops finally discovered him to be hiding on a farm belonging to Richard Garrett and surrounded the barn in which he and Herold were sleeping. The two men were ordered to surrender: Herold complied, but when Booth failed to drop his weapon and come out, the barn was set ablaze. A trooper named Boston Corbett, who was watching Booth through a gap in the barn's siding, shot the assassin. Whether Corbett can be said to have "assassinated" Booth is problematic — the deeply religious Corbett sometimes claimed that he had shot Booth because "Providence directed" him to do it or because he "did not want Booth to be roasted alive," but he also testified that he shot Booth because he "saw [Booth] in the act of stooping or springing and concluded he was going to use his weapons."

Oswald left the warehouse from which he shot Kennedy and was arrested in a movie theater a little over an hour later by police officers who had no idea who he was. (Oswald was initially arrested only for the murder of Dallas police officer J.D. Tippit, whom he shot while in flight; his connection to the Kennedy assassination was not established until later.) Oswald was captured alive and remained in custody for two days before being gunned down by Jack Ruby, a private citizen.

Other differences: Booth was shot in the back in the neck and lived for another three hours; Oswald was shot in the abdomen and died within minutes of his arrival at Parkland Hospital.
A month before Lincoln was assassinated he was in Monroe, Maryland.
A month before Kennedy was assassinated he was in Marilyn Monroe.
This is a latter-day addition to the list and nothing more than a bit of salacious humor. Even as a humorous coincidence it fails the test, as Marilyn Monroe died well over a year before Kennedy's assassination.
Read more at http://www.snopes.com/history/american/ ... zv4JYwQ.99