So...Ned Spengler (or Spangler) was tried as a co-conspirator and sent to the Dry Tortugas with Dr. Mudd.
Ned was basically a town drunk, hung out with Booth, helped around the theater, etc. Booth came up on his horse that night, I believe back of the theater, asked Ned to hold his horse for a minute and tossed him some drinking money. The rest, as they say, is history.
For that, he was convicted and imprisoned. He wrote a letter that was later published in his hometown paper, proclaiming his innocence, and asking that his family send some hooks, line, etc. to him in prison, so they could fish and supplement their rations.
My great grandmother traced our family back through and discovered this in the 1970's/1980's....my aunt has tried to verify the link, and there are definitely Spangler/Spengler in the line, but the connection to Ned is a little nebulous, but it's still part of the family lore.
Also have a however-many great uncle who was supposedly killed at the Little Bighorn with Custer....though his name (Silas Pierce) isn't on any of the rolls of the known dead. I did find a Silas Pierce who was a member of the 31st Pennsylvania Volunteers during the Civil War, but I don't even know that he's the right one. I suspect the truth is far less interesting, though his Civil War service would be worth noting.