It depends on what time period you are referencing with African immigrants. Back in the 1500s, African people came to the Americas because of Slave Trade, but later on, they came to the United States under their own free will. Slave Trade forced African people on ships into the Americas, in which they stayed as slaves or did forced labor in a harsh system.
In the 1900s and later on, African immigrants came to America to seek asylum or safety in the United States because of problems going on in their countries. For example, in Rwanda, in the 1990s, there was some major problems going on such as genocide (mass killing of people) and some people came over to America to escape these hardships.
Also, another way they are different would be their culture that they brought. Their influence of music and African culture was very different as compared to other cultures from Europe.
