Is the killing an entire group of people just because of their ethnic identity.

Killing an entire ethnic group is called genocide

That would be what you call a "genocide"

The answer is closed primary.

The changes to agriculture in the united states since 1900 is that increased mechanization has increased food production, thereby increasing the need for labor. there has been an increased need for higher speeds of food production due the fact that the population in the united states continues to rise.