How does maryland v. mcculloch relate to federalism?

Well.. for one:
They helped balance the Federalism..

Chief Justice Marshall's decision in McCulloch v. Maryland says an action or law of a state cannot impede the valid constitutional exercises of power by the Federal government. By demarcating a clear line between federal and state power, it allowed for a more cooperative relationship between states and the federal government
Hope this helped :)

The Federalist Papers are a series of 85 essays written in 1787 and 1788 to promote the ratification of the United States Constitution. I found it to be the equivalent of reading a 600 paged legal brief written by an 18th century lawyer. Actually, that's exactly what it is. I found these lectures helpful in describing the debates that took place at the time these papers were written. I was impressed at the extent and variety of the arguments of "The Federalist Papers" in defending the proposed Constitution. I guess I can be thankful to live in a country where so much effort and care was put into forming the government.