Complex sentence: In 1933, while working for the Pittsburgh Coal Company in Minneapolis, Dobbs joined the Teamsters and after getting to know the three Trotskyist Dunne brothers, (Miles, Vincent & Grant Dunne) and Swedish socialist Carl Skoglund, he joined the Communist League of America.
Split into simpler sentences: In 1933, while working for the Pittsburgh Coal Company in Minneapolis, Dobbs joined the Teamsters. After getting to know the three Trotskyist Dunne brothers, (Miles, Vincent and Grant Dunne) and Swedish socialist Carl Skoglund, he joined the Communist League of America.