What does frederick douglass mean when he say "american reigns without a rival"

Ineed with what i should write for my research paper. my topic is history of slavery. 1800 words. all i need is what to write in each paragraphs. like when the research paper has titles for each paragraph and it explains the tile in each paragraph. for example when did slaverh begin? why did it begin like an outline.

Match each model with its name and the name of the scientist who created it.

Define”to walk with a large group of people who are supporting something”