What is the name of the syatem in which each branch of the u. s govertment can limit the action of the other branches?

Allocation of distinct but equivalent controls within the three offices of the US Government is called Separation of Powers which is the unique aspect of the American constitution.  

System of checks and balances allows scrutiny of one division over the other. It is appreciated by the whole world who desired complete democracy. This system ensures that no branch of the US Government becomes too influential while wielding their commands.

For example president can reject the laws that are passed by the congress and the congress can overrule the veto of the president if it is required. Thus the presidential power is delimited and all the three branches are given with equal value of responsibilities.

the population grew a lot and was making more money

the group i'm selecting: greeks.

a first group of greek immigrants came to the us in the 1850s. the second group came to america starting in the 1890s due to economic opportunities they didn't have back in their home caused by the hardships of ottoman rule. greek immigration was 90% male, many of them expected to work and return to greece after earning enough capital, but ultimately had to remain in the us after the greek genocide.