Mexico expropriated the foreign oil companies in 1938, crowds brought chickens and jewelry to help pay, and Mexico paid the companies in full

In 1937 Mexican oil workers went on strike. On 18 December 1937 an arbitration board ordered the foreign companies to pay 26 million pesos in lost wages. On 1 March 1938 the country's highest court upheld the award, and the companies did not pay. On 18 March 1938 President Lázaro Cárdenas announced the expropriation on the radio, two hours before he told his cabinet. Mexican Eagle, a Royal Dutch Shell subsidiary, produced over 60 percent of Mexico's oil; Jersey Standard and Standard Oil of California produced about 30 percent. On 12 April 1938 a crowd gathered at the Palacio de Bellas Artes to donate toward the debt to the companies, with gifts "from chickens to jewelry." A decree of 7 June 1938 created Petróleos Mexicanos (Pemex). The companies imposed an embargo. Mexico's oil exports fell by half, and Nazi Germany became its main customer. Britain withdrew its ambassador, and Mexico broke relations. On 2 December 1939 the Mexican Supreme Court upheld the expropriation. In 1942 Mexico agreed to pay American firms about $29 million. The British held out until 1947 and received $130 million. A 2011 study by Noel Maurer found that Mexico "more than fully compensated" the companies, and that oil wages and government oil revenue did not rise. In 2013 President Peña Nieto opened the sector to private investment. March 18 is a civic holiday.