(upbeat music) [Narrator] This pamphlet may be one reason why we have a Bill of Rights today.

For over 100 years, the true author of this famous anti-Federalists pamphlet remained a secret.

Originally published under a pseudonym, and later credited to a man, 1788's observations on the new Constitution was actually the work of a woman activists Mercy Otis Warren.

A fierce patriot, Warren opposed ratification of the US Constitution, fearing a strong central government would set the country back a decade into tyranny.

In response, she outlined common anti-Federalists criticisms in an easily distributed pamphlet.

Ultimately, she and her supporters did not win the fight against ratification, but they did win something still impacting us today.

Historians now correctly credit Warren for her influential work, arguing for a bill of rights.