GDG- OT: Marching Speed / Distance

[Jim Beeghley]

Hi,

This is sort of off topic but I was wondering if someone knew how fast 
Civil War soldiers marched.   For example, how many miles (on average) 
did a unit cover in a day?

Or, I know that it is about 25 miles from Chambersburg to Gettysburg.  
What time did the Confederates leave there and arrive in Gettysburg?

Thanks for the help.

Jim Beeghley