How has America's idea of equality changed over time

America used to be a place of slavery where only white men ruled and women and blacks, asians, mexicans, etc. were considered lesser and were forced into submission. In our current society things are change to where all are considered equal and there are laws against people being segregated from working or being in places of power, it even encourages women and blacks into higher society places. but still our world isn't perfect and people still dont want women presidents and others still want to eradicate blacks from our society.

I don't know if this is what you need but here is this

The overall U.S. population growth has shifted south and west, with Texas and Florida now among the most populous states. RACIAL AND ETHNIC DIVERSITY As we've grown, we've also become more diverse. Women still make less money in the workplace than men...but the wage gap is shrinking.

Revolution

The economic expansion between 1815 and 1860 was reflected in changes in American society. The changes were most evident in the northern states, where the combined effects of the transportation revolution, urbanization, and the rise of manufacturing were keenly felt.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.