William E. Slafer 
Last updated: 22.06.17
All that can presently (February 2016) be gleaned about by internet searching is that William E. Slafer is the one-off composer of Brooklyn Daily Eagle Bridge Crush March (1907) published by Goetz & Co., Brooklyn, New York, USA.
Surfers are welcome to contribute information about this composer.

Further sheet music at DBE: ON HOLD