161 Years since the Army of Northern Virginia started crossing the Potomac River to enter the State of Maryland on September 4th, 1862.
The intention to enter Maryland during the War was because many pro-secession Marylanders were being heavily suppressed by the Union Army using more "Authoritarian" Tactics you could say, and many were being imprisoned for supporting secession in any way.
Many believed that Maryland was being held in the Union by force since Lincoln knew that if Maryland Seceded, D.C.
Would be surrounded by the CSA.