* Frederick Douglass did not invent any notable devices or machines. However, he was an influential speaker, writer, and abolitionist who made significant contributions to the fight against slavery and for civil rights.
Discoveries:
* Douglass's most significant discovery was the power of public speaking and writing to promote social change. Through his speeches, articles, and books, he helped to educate and inspire people about the horrors of slavery and the need for its abolition.
* He also discovered the importance of political activism and organizing. He was involved in various political campaigns and organizations dedicated to fighting for the rights of African Americans, including the abolitionist movement and the women's suffrage movement.
* Through his own experiences and observations, Douglass also discovered the resilience and determination of African Americans in the face of oppression and discrimination. He highlighted these qualities in his writings and speeches to demonstrate the strength and capabilities of his community.