The economy of these early civilizations was based on

warfare
agriculture
industry
production

do you have a list of sources to choose from?

no

explanation:

not everyone in america is free. it is has always been a unequal society. and yet people come in swarms, in search of better lives. some are brought as children, unaware, unknowing. some arrive and just don’t leave. they build lives, pay taxes, raise families. some enter illegally, fleeing persecution in their home country.

there are many reasons why human beings are so attracted to america, despite its history of bitterness towards immigrants.

there are almost two million immigrants brought to the us when they were children. president donald trump and his collaborators are determined to rid the us of as many undocumented immigrants as they can, and stop others from coming because none of their ancestors were immigrants.

america has so many things and yet it lacks the one thing that humanity needs to fully thrive. and so this country will not be at peace in itself until it resolves the pain at the heart of slavery, attacking immigrants, and crumble the rights of those with less power.