Final answer:
During the Great Depression, trains, bicycles, and cars were all legal forms of transportation. The economic downturn affected the affordability and usage of these transport modes, but they remained lawful.
Step-by-step explanation:
The question regarding legal transportation during the Great Depression seems to have a typo or confusion with the period referenced. For clarity, during the Great Depression, which occurred in the 1930s following the stock market crash of 1929, all conventional modes of transportation were legal. This includes trains, which were a primary mode for long-distance travel; bicycles, which provided an affordable and accessible means of transportation; and cars, though their use was impacted by the economic downturn, they remained legal and were utilized by those who could afford them.
Considering the context provided about the Depression of 1893 and the use of federal troops to operate trains, it is important to note that the transportation industry faced significant challenges during various economic depressions but did not become illegal.