On 4 June 1949, in the aula magna of liceo Visconti in Rome, Republicans and Social Democrats founded the Italian Labor Federation (FIL). Later, in the summer of 1949, some trade unionists of the autonomous socialist faction led by Italo Viglianesi split from CGIL, following the example of autonomous socialists led by Romita who split from PSI and founded the United Socialist Party (PSU) in December 1949. The attempt of Viglianersi group to join the FIL was blocked because FIL, under American pressure, was considering merging with the Catholic LCGIL. The American embassy (US Department of State) and the American Federation of Labor were pushing to have a big unified and strong "not communist" trade union centre to stand out against the "red" CGIL.