Complex sentence: Sarah Moore Grimké was the author of the first developed public argument for women's equality and she strived to rid the United States of slavery, Christian churches which had become "unchristian," and prejudice against African-Americans and women.
Split into simpler sentences: Sarah Moore Grimké was the author of the first developed public argument for women's equality. She strived to rid the United States of slavery, Christian churches which had become "unchristian," and prejudice against African-Americans and women.