Radio Act of 1912
Initiated by the Titanic disaster, the Radio Act of 1912 was signed by President Taft to mandate seafaring vessels monitor distress signals and that all United States radio stations must be licensed by the federal government. This was the first piece of United States legislation which would impact Amateur radio broadcasting.
"100 Years of Amateur Radio Licensing", initially appeared in the ARRL QST Magazine of August 2012, and is reproduced here with their express permission. (pdf, 310Kb)