Simultaneous with the last New York struggle, an even larger tenants’ strike broke out in the tenement (conventillo) districts of Buenos Aires, and by October 1907 an estimated 10 percent of the city’s population (about 120,000 residents) was refusing to pay rent to their landlords. The largely immigrant Argentine working class was the fastest growing in the world at the turn of the century, and Buenos Aires, which doubled its population in the decade after 1895, was an overcrowded boomtown where rack-renting was profligate. The more energetic of the country’s two labor federations, the anarchist Federación Obrera Regional Argentina (FORA), had decided at its Sixth Congress in 1906 to encourage the formation of a tenant strike movement. The strikes a year later were largely unsuccessful in their immediate objectives, but, as James Baer emphasizes, were strategically important in mobilizing proletarian women and non-union workers for general strikes that were soon to follow.