Like Washington and Jefferson, he championed liberty. Unlike the founders, he freed his slaves

It was 230 years ago Sunday that Robert Carter III, the patriarch of one of the wealthiest families in Virginia, quietly walked into a Northumberland County courthouse and delivered an airtight legal document announcing his intention to free, or manumit, more than 500 slaves.

He titled it the "deed of gift." It was, by far, experts say, the largest liberation of Black people before the Emancipation Proclamation more than seven decades later. On September 5, 1791, when Carter delivered his deed, slavery was an institution, a key engine of the new country's economy. But many slaveholders -- including founding fathers George Washington, Thomas Jefferson and James Madison, who knew Carter -- had begun to voice doubts.