Complex sentence: Terry took a keen interest in social and political issues and through Edith Halpert was introduced to the works of African American artists including Jacob Lawrence, whom Terry represented for 25 years, Raymond Saunders and Horace Pippin.
Split into simpler sentences: Terry took a keen interest in social and political issues. She showed the works of African American artists including Jacob Lawrence, whom she would represent for 25 years, Raymond Saunders and Horace Pippin.