My Journey on Lincoln's Assassination

[L Verge]

I don't think that Mrs. Surratt had advanced notice that she needed to go to the tavern. The Calvert letter was dated April 12, and I believe she received it sometime before 2 pm on the 14th. It was likely sheer luck that Weichmann took Stanton's invitation to take the afternoon off, which gave Mary the opportunity to act quickly regarding Calvert's demands. He had already sued her husband twice for debts owed since 1852, so Mary didn't need to mess around!

Also, if I remember correctly, Weichmann went to church after getting off work and before coming home. Doesn't sound like anything was pre-arranged travel-wise. The fact that Nothey wasn't waiting for them at the tavern also indicates that everything was spur of the moment.