What Was The Role of David Herold

[L Verge]

Traffic into Washington had been the threat throughout the war - especially at that particular bridge (and Bennings) because it led into "hostile" territory known as Southern Maryland. Other bridges led into Virginia, and the close environs of that state to D.C. were in Union hands quickly after the war started.

As for relaxing orders about crossing the bridge, John and Jerry focus on the sentries doing their duty. At that particular time of celebrations, my instinct tells me that "tight security" became a matter of personal choice on the part of Cobb and other sentries - especially if the people they stopped seemed reputable and well-dressed.

Finally, about how Booth knew who had killed whom, I still think the scenario of Herold as point man rings true. Escort Powell and wait to hear the cry of murder, assume Powell has done his job; rush over to the Kirkwood and see absolutely no sign of turmoil there and figure Atzerodt had chickened out (or to placate you, that Herold couldn't get to the weapons which he should have taken all along); head to the appointed bridge to meet up with Booth and skedaddle.