What significance for the history of the early republic does Ellis attribute to the friendship?

The men who became the Founding Fathers first developed relationships with each other as friends. Fighting beside one another, possessed by the spirit of ‘76, they formed a idealistic brotherhood intent on freedom. The decades that followed can be understood in terms of their persistent or declining friendships. Washington's close friendship with Hamilton was essential towards the formation of the Federalist party, for instance. Jefferson traded a friendship with Adams for a political collaboration with Madison, which revealed his shifting political obsessions. In fact, the relationship between Jefferson and Adams is arguably the central one of the book; Ellis explores how politics severed the close ties forged by the Revolution, but how time and perspective facilitated a renewal of that friendship. Much of Ellis's intention in this book is to consider how these friendships either affected or were affected by the turbulent times in which these men lived and formed a new government.