What is one positive result of the columbian exchange? this is u. s history

The exchange of plants and animals was probably the best of the results, the worst of which would be the slaves.

Ifound this on google “the existence of agglomeration economies is central to the explanation of how cities increase in size and population, which places the phenomenon on a larger scale. the concentration of economic activity in cities is one reason for their development and growth.” i hope this you for what your looking for.