In 1783, Breck attended the Royal Military School of Loreze, France.

On December 24, 1795, he married Jean Ross, the daughter of a leading Philadelphia merchant.

In February 1821, he was the lead sponsor of a law that would have immediately emancipated all enslaved persons living in Pennsylvania.

When this failed, he sponsored another bill which would have amended the state's existing gradual abolition law.

In 1861 he spoke publicly at a meeting in Philadelphia urging the people to preserve the constitution he had been alive to help form.