How to save JFK, save Lincoln, and stop World War II...without killing anyone.

I've been thinking about time travel. Lots of strategies involve preventing disasters by killing the perpetrators, such as Hitler or Lee Harvey Oswald. But should a life, even millions of lives, be saved by taking a life? I've come up with three common time travel scenarios whose aims could be achieved without any bloodshed.

Please note that these theories have not been tested. Your alternate universe may vary.

Instead of killing Hitler... buy his paintings

Before going into politics, young Adolf Hitler was a painter. For five years, he lived in Vienna and painted mostly buildings and landscapes. He wasn't very successful and may have been at a career crossroads when World War I broke out. Hitler served in the German army and took his paints with him, creating art during the long stretches between battles.

Devastated by defeat, which he blamed on civilian leaders and Marxists in Berlin, Hitler gave up on art. He became an internal intelligence agent for the government, spying on the German Workers' Party. His transition to politics had begun.

But what if his art career had taken off?

Sure, Hitler would still have had plenty of ideas about politics after the war, but fame and wealth as a respected artist could have drawn him away from government. He considered himself an artist throughout his life, saying in late in 1939, just before invading Poland, "I am an artist and not a politician. Once the Polish question is settled, I want to end my life as an artist." If he was successful in his artistic pursuits, would he have ever turned back?

I recommend traveling to Vienna in 1910, meeting Hitler, buying his works, and commissioning others. It's OK if you're Jewish—most of his customers at the time were. Keep in touch with him during the war and, once his tour is over, encourage him to keep painting. Buy his works. Sell them. Exhibit them. Keep him happy and distracted.

There were more factors leading to World War II than just Hitler, of course. But killing him wouldn't solve those problems, either. This strategy just might lead to a shorter, smaller-scale version of the war, or maybe no war at all, saving millions of people.

Instead of killing Oswald... cancel JFK's Texas trip

It's hard to know if Lee Harvey Oswald would have taken a shot at JFK if the motorcade hadn't rolled right underneath his workplace. It's easier to know that trying to take out Oswald just moments before the assassination, while dramatic, is usually unsuccessful. Instead of killing Oswald or disrupting his life (which was already a struggle), why not take the president out of the equation?

Kennedy and Johnson were in Texas as an early campaign stop for the 1964 election. Southern Democrats, angered at civil rights legislation, were already causing trouble: In 1960, Dixiecrat candidate Harry Byrd cut into the party's "Solid South" by winning Mississippi and half of Alabama (which split its electoral votes back then). The Democrats also lost Tennessee, Virginia, and Florida. They had won Texas, possibly thanks to native son Johnson on the ticket, but only by 2%, about 45,000 votes in a state of 9.6 million people. At a campaign meeting a few weeks before his death, he zeroed in on Texas and Florida as must-win states and made plans to visit both.

But did JFK need to visit Texas to win Texas? In fact, did he even need to win Texas?

He never got the chance to run the next year, but LBJ did. Even after signing the Civil Rights Act of 1964, which lost him the five Deep South states, he won Texas. He also brought back Tennessee, Virginia, and Florida. And just about every other state. You see, in 1964 -- Kennedy or no -- the Republican candidate was Barry Goldwater, a far-right conservative who alienated many members of his own party. Northeastern Republicans like Nelson Rockefeller did not campaign for him. The last GOP president, Dwight Eisenhower, disliked Goldwater (the feeling was mutual), and made just one campaign commercial on his behalf. He seemed eager to use nuclear weapons against Russia and joked at a press conference, "Sometimes I think this country would be better off if we could just saw off the Eastern Seaboard and let it float out to sea."

The result was one of biggest presidential landslides of all time: 44 states (plus DC) to 6, and 486 electoral votes to 52. With that kind of cushion, Kennedy could have continued to push for civil rights and lost Texas, and even the entire South, and still won re-election.

I recommend convincing JFK or his campaign staff that a Texas trip isn't necessary, either because LBJ will help win the state or that it's safe to lose. Put the emphasis on winning back the next-biggest Southern states, Florida and Virginia. With so many factors contributing to the assassination (whether through coincidence or intention is up to you), even delaying the trip until, say, February of '64 might mean that Oswald wasn't employed along the motorcade route, or his hatred of JFK would have cooled, or he simply wouldn't have been able to pull off the operation.

Instead of killing Booth... get his autograph

Booth's plan was simple: Ask for permission to enter Abraham Lincoln's theater box, then wait for the play's funniest line. The crowd's laughter would distract the audience and cover the sound of his entry before he fired his gun. Thus, timing was crucial.

Booth was a well-known actor and audience members thought nothing of him roaming the seats as the play was in progress. He wrote a note to the usher outside Lincoln's box—there was no other security—who took it to the president and then opened the box's door for him. So his appearance wasn't a secret.

As a time traveler, you could use that to your advantage. I suggest recognizing Booth, approaching him, and asking for his autograph. Engage him in conversation. Make sure everyone around notices his presence. If you shake his hand hard enough, or even hug him, you might dislodge his pistol or the knife with which he stabbed people who tried to stop his escape. Best of all, you can throw off his timing, so the big laugh happens while he's still outside Lincoln's door. You're not doing anything suspicious or even malicious; you're just a big fan of Booth's.

Remember, Booth's plot was part of a wider conspiracy; his associates were supposed to kill the vice president and the secretary of state. But one of his confederates lost his nerve and other was only able to wound Secretary Seward. Thus, the plot was found out pretty quickly. Just a few hours after those attempts, Lincoln would surely have been given extra security and may have canceled public appearances. And either of the other two conspirators might have ratted Booth out, ending the threat for good.

Jason Ginsburg writes about history, movies, and science fiction. He works for Discovery Channel.

Jason Ginsburg

The Time Traveler's Guide to Peaceful Intervention