What were the declarations passed in 1798 and 1799 that claimed each state has the right to decide whether federal laws are constitutional and to nullify laws?

The Kentucky Resolutions of 1798 argued that each individual state has the power to declare that federal laws are unconstitutional and void. The Kentucky Resolution of 1799 added that when the states determine that a law is unconstitutional, nullification by the states is the proper remedy.

Explanation:

there are hundreds of postives ways to unite a country with another country here are a   few

1 peace treaty's peace treatys

are basically a document signing a allliance with one country and another.

2 gift

what i mean by this is for example how the french gave the americans the statue of libery a gift of peace.