Complex sentence: During the 1930s and 1940s the program evolved into the Lacy Kirk Williams Institute, which attracted national attention; its attendants included the Rev. Martin Luther King, Jr. and Rev. Jesse Jackson.
Split into simpler sentences: During the 1930s and 1940s the program evolved into the Lacy Kirk Williams Institute. The institute attracted national attention and its attendants included the Rev. Martin Luther King, Jr. and Rev. Jesse Jackson.