Complex sentence: Her most renowned effort is a petition federal recognition as a Native American which resulted in the Nipmuc being placed on'active consideration' for federal recognition by 11 July 1995.
Split into simpler sentences: Her most renowned effort is a petition for Nipmucs to be granted the status of one of the Federally recognized tribes of the Native American peoples. This resulted in the Nipmuc being placed on "active consideration" for federal recognition by 11 July 1995.