How did the supreme court ruling in plessy v. ferguson support segregation laws

What event was one of the greatest factors that led to massive emigration from ireland to the united states in the mid—1800s

In a publicly held corporation, - o stockholders rarely trade their stocks o stocks are not usually traded at stock exchanges o a large number of stockholders can buy and sell stock o family members are excluded from holding stock

Rank the following from most to least devasting: ordovician, permaian, cretaceous, pleistocene