Waldo Place's name origin is not clear. It already appears on the maps of 1860-76, and thus is likely to have been a revolutionary war holdover. Was it named for Abigence Waldo, MD, a surgeon with Washington at Valley Forge and possibly here? Which Waldo? or perhaps "Where's Waldo?" :) 
- Griffin et al, Dustin (2003). Englewood: Historical Sketches. Englewood Historical Society. p. 52.