If you walk into a corn field in Iowa about 50 km south of the Minnesota/Iowa border on Interstate 35 in northern Iowa you will see this monument. The same man now owns the corn field and the venue where the big 3 played their last performance.
Just north of this exit in Clear Lake/Mason City, Iowa is an Iowa State "Welcome Center" that has some good reading material on that historic event.
I don't know what exactly was done legislatively but I'm sure they don't allow 21 year pilots, who have failed their instruments tests, to fly in bad weather and are waken in the middle of the night, to fly anymore.