By August 1919, only months after its founding, the CPUSA had 60,000 members, including anarchists and other radical leftists, while the more moderate Socialist Party of America had only 40,000 members.
Only months after its founding had 60,000 members. This was by August 1919. This was including anarchists. This was including other radical leftists. The more moderate Socialist Party of America had only 40,000 members. The CPUSA was its founding.