April 19, 1865 funeral procession

[Eva Elisabeth]

Scott and Kees mentioned 42 different engines - that meant 3,5 different each day. Why??? Reasons for changing engines I could think of are entering a different company's "territory" (but were there so many different companies?), and/or different gauge (which would also require to change the cars). Were there so many different engines also used for the inaugural journey? Thanks for any hint!