Complex sentence: Little or no attempt was made to recruit African-American or other women minorities until October 1944, when President Roosevelt approved of accepting African-American women into the women's reserve, under pressure to do so by African-American organizations.
Split into simpler sentences: Little or no attempt was made to recruit African-American or other women minorities until October 1944, when President Roosevelt approved of accepting African-American women into the women's reserve. But, he was under pressure to do so by African-American organizations.