FIELD DAY: A Mirror of Amateur Radio History by Rol Anders (K3RA).
Steeped in tradition and mystery, today’s Field Day evolved from
humble beginnings in the Golden Age of Radio. Anything but stable,
Field Day rules and practices have changed radically since the 1930s.
Full article at:
https://hams.soe.ucsc.edu/sites/default/files/History%20of%20Field%20Day.pdf