Go back to the early 30's and give Japan a textbook detailing the WW2 in Asia War and see how far they get.
Go back to 1966, sleep with Dianne Chandler in her prime.
I’m not sure how the Maple Leaf Flag is visually pleasing? I think Diefenbaker said it best, when referring to the Maple Leaf Flag: "a flag that Peruvians might salute".
Shoot Muhammad, his family and all his friends and also burn all his writings, undoubtedly.
Or Jesus and his followers as well, of coz.
I'm with RogueBeaver. I'd whack Princip. Archduke lives.
If it's US history, I'd whack Booth. Lincoln lives, Reconstruction isn't messed up, and we are POTENTIALLY saved 100 years of pain.