The Civil War had ravaged the Spanish economy. Infrastructure had been damaged, workers killed and daily business severely hampered. The economic recovery was very slow and it was not until the second half of the 1950s that the economy of Catalonia reached the prewar levels of 1936. After an initial period in which Spain tried to build an autarky, in which the economy improved little, Franco's regime changed its economic policies in 1959 and in the 1960s and early 1970s the economy entered a period of rapid economic expansion that became known as the Spanish Miracle. International firms established their factories in Spain: salaries were relatively low, strikes were forbidden, labour health or real state regulations were unheard of and Spain was virtually a virgin market. The period was marked by agricultural modernization, a massive expansion of industry and the start of mass tourism, which it was concentrated on the coast (Costa Brava in Girona and Costa Daurada in Tarragona). As industry in Catalonia expanded, workers migrated from rural areas across Spain (particularly Andalusia, Extremadura, Murcia and Galicia), to work in Barcelona and its surrounding area, turning it into one of Europe's largest industrial metropolitan areas, which in turn led to dramatic urbanisation. Working-class opposition to Franco began to appear, usually clandestinely, and most notably in the form of the Comisiones Obreras ("Workers Commissions"), a return of trade union organizing, and the revival of the PSUC, while the students' protests turned frequent. In the 1970s democratic forces united under the banner of the Assemblea de Catalunya ("Assembly of Catalonia"), demanding political and social freedom, amnesty for the political prisoners, the reestablishment of the autonomy of Catalonia and the collaboration with the democratic forces of the rest of Spain.