TrampTramps are itinerants who travel from place to place, traditionally tramping, that is, walking. While they may do odd jobs from time to time, tramps aren't looking for regular work. This is in contrast to hobos who travel from place to place (often by stealing rides on freight trains) looking for work. Both these terms (and the distinction between them) were common between 1880s to 1940s, and were not limited to the Great Depression.
See also: vacilandos.