text: In 1938, Humble Oil built  a mile-long wooden trestle with railway tracks into the sea at McFadden Beach on the Gulf of Mexico, placing a derrick at its end – this was later destroyed by a hurricane.
  In 1945, concern for American control of its offshore oil reserves caused President Harry Truman to issue an Executive Order unilaterally extending American territory to the edge of its continental shelf, an act that effectively ended the 3-mile limit "freedom of the seas" regime.
  In 1946, Magnolia drilled at a site  off the coast, erecting a platform in  of water off St. Mary Parish, Louisiana.
  In early 1947, Superior Oil erected a drilling and production platform in  of water some  off Vermilion Parish, La.  But it was Kerr-Magee, as operator for partners Phillips Petroleum and Stanolind Oil & Gas that completed its historic Ship Shoal Block 32 well in October 1947, months before Superior actually drilled a discovery from their Vermilion platform farther offshore. In any case, that made Kerr-McGee's well the first oil discovery drilled out of sight of land.
  When offshore drilling moved into deeper waters of up to , fixed platform rigs were built, until demands for drilling equipment was needed in the  to  depth of the Gulf of Mexico, the first jack-up rigs began appearing from specialized offshore drilling contractors.