How did Eli Whitney’s system of interchangeable parts improve gun-making

The 14th amendment overruled the supreme court case of dred scott vs. sandford. the landmark supreme court case determined which of the following points? a.slaves could not be citizens b.non-landowners could not be citizens c.blacks could not be citizens d.all persons born or naturalized in the united states vary differently in citizen status.

Between 1870 and 1916, approximately how many immigrants came to the united states? 10 million 25 million 75 million 125 million

During what century did muhammad recieve his first revelation from god