The first continental red beds were deposited during the eon, and passive continental margins became common during the eon.

Proterozoic, Proterozoic

Explanation:

The proterozoic eon is the younger of the two divisions of Precambrian time. The older if the two is the Archean eon. The Proterozoic Eon is a period from 2.5 billion to 541 million years ago and is often divided into the Paleoproterozoic era, the Mesoproterozoic era and

Neoproterozoic eras. Proterozoic rocks important sources of metallic ores, such as iron, gold, copper, uranium, and nickel.

During this time, the atmosphere and oceans changed significantly and caused developments such as high increase in oxygen.

Proterozoic rocks are evidence of many primitive life-forms such as bacteria and the Ediacara fauna.

here are some major conflicts i found. maybe pick one and do more research on it. (cause i ain't writing 6 paragraphs)

in 1877, the nez perce war took place.

1881 - president james garfield was assassinated.

1882 - the chinese exclusion act was passed.

1883 - a decision in the civil rights cases legalized racial segregation in the united states.

1887 - the dawes act was passed.

1893 - the panic of 1893 took place. (what a creative name)

and there are probably other topics you can find if you just search up "united states timeline," or "conflicts in the 19th century for america."

then once you find a topic you like find out how it affected the people of america and what not. (sorry if this feels a bit short changed, history was and never will be one of my strong topics)