Here's an idea...
POD 1852: Junius Brutus Booth senior, instead of dying while returning from California, lives and returns to Maryland where he joins his wife Mary Ann Booth and continues building “Tudor Hall” his new home at Bel Air Maryland.
-John Wilkes Booth as a result remains at St. Timothy’s boarding school instead of returning home. As a result he develops an even keener interest in the military and flirts with the idea of becoming a soldier and earning glory for his family.
-Due to the coaching and insistence of his father Edwin Booth makes an earlier “re-entrance” into the world of theater and becomes a renowned American tragedian following in his father’s footsteps. His brother’s acting fame coupled with that of his fathers’ pushes Booth even further towards joining the military, causing him to ask his father to call in some favours and use his influence to get him into West Point.
-Booth arrives at West Point in 1856 at 18 and immediately thrives, building off his experience at St. Timothy’s. He becomes one of the top students in his class, though he gravitates towards the Cavalry rather than towards artillery and engineering like some students. Booth’s time at West Point proves to be a formative period in his life where he makes many friends in both Northern and Southern Camps and further refines his political views supporting the Know Nothing Party in 1856 and being somewhat dismayed at the calls for secession as well as the growing abolitionism of the North.
-Booth graduates from West Point near the top of his class in 1860 just ahead of the pivotal election. William Seward is elected POTUS having won the presidency instead of Lincoln. Lincoln meanwhile runs for the House of Representatives in Illinois and wins, eventually being elected Speaker of the House.
-With the secession of the rest of the Confederate States, Booth remains loyal to the Union despite troubles in Maryland. Booth serves with distinction during the Civil War, rising through the ranks rapidly due to the paucity of able cavalry officers in the Union ranks as well as his aggressiveness, intelligence, and charisma. In 1863 Booth becomes one of the youngest Union Brigadier Generals at 25 and commands a brigade under Buford. Booth acquits himself well at Gettysburg attracting some publicity after he assumes the role of a seriously wounded Buford. Later, Booth will succeed Buford as commander of his division and serve with distinction for the remainder of the war.
-Lincoln loses his bid for re-election in 1862 this coupled with a freak carriage accident leaves him struggling with injuries and headaches that effectively sideline him for the rest of the war. However Lincoln does become an outspoken proponent for Civil Rights.
-At the end of the Civil War, Booth musters out of the army and returns to Maryland where his popularity and oratory skill prompt several calls for him to run for office. Booth runs for Congress, receiving the Republican nomination though he runs as a moderate. Booth serves well in Congress but opposes radical reconstruction. His support for Johnson’s policies lead him to be pushed out of the GOP so he runs as an independent and later a Democrat. He later campaigns for Horace Greeley’s Liberal Republican party in 1872 and the Democrats in 1876. The democrats nominate Thomas Hendricks who balances the ticket with the young Booth. Booth campaigns actively and contributes to the Democrat victory greatly. Following the election of Hendricks, the president dies resulting in Booth becoming the youngest president in American history. He is later assassinated by Lincoln who after the death of his wife in the late 1860's becomes infatuated with advancing the cause of Civil Rights and sees the new president as a major obstacle. He shoots Booth in Ford Theater in 1879 attending a showing of "My American Cousin".