The constitutional convention that met in Philadelphia during the hot summer of 1787 was composed primarily of men who favored a consolidation and strengthening of the federal government to replace the loose confederation of sovereign  and independent states existing under the Articles of Confederation. The case of New York was a little different. New York sent three delegates to the convention. Alexander Hamilton was one of the most ardent supporters of a strong central government, but the other two delegates, John Lansing and Robert Yates, had been chosen by the populist New York governor, George Clinton, as foils for Hamilton, because they were strong supporters of state sovereignty who would oppose a new Constitution.
After the Constitution was signed in September 1787 (only Hamilton from New York signed it), the document went to state conventions for ratification. Anticipating a hard-fought battle in New York’s convention, Hamilton enlisted James Madison of Virginia and John Jay of New York to help him write essays—newspaper editorials, essentially—closely arguing the case for the new Constitution. The supporters of the Constitution were called “federalists,” hence the title The Federalist Papers. Opponents were called “antifederalists,” and in New York they were led by the powerful governor, George Clinton, who didn’t want to see his personal power, or the power of his state, diminished, as he thought it would be under a strong central government.
In Federalist 1, Hamilton makes an appeal for moderation on both sides of the debate. He realizes that there were good men on both sides of the issue, as well as men driven by motives other than the good of their country: “Ambition, avarice, personal animosity, party opposition, and many other motives, not more laudable than these, are apt to operate as well upon those who support as upon those who oppose the right side of a question. Were there not even these inducements to moderation, nothing could be more illjudged than that intolerant spirit which has, at all times, characterised political parties.”
The Federalists were, for the most part, men of property, education, and rank in society. Hamilton, though he came from a poor and obscure background, was a prosperous lawyer and the son-in-law of one of the most prominent men in New York, Philip Schuyler. Hamilton’s collaborator, John Jay, was also a lawyer (he became the first Chief Justice of the U.S. Supreme Court) and had married into the prominent Livingston family. The Schuylers and the Livingstons were the closest thing New York had to an aristocracy. The charge of elitism, and of promoting an actual aristocracy, haunted Hamilton throughout his career, and was frequently used against the Federalists in general.
Meanwhile, the Antifederalists (led in New York by Gov. Clinton) portrayed themselves as populists and true democrats. One of the important things that The Federalist reveals is a distrust on the part of Hamilton, and shared by other Federalists, of democracy. Hamilton believed that radical democracy, manipulated by a charismatic demagogue (he was thinking of Clinton), was more likely to result in tyranny than was a strong centralized government. He wrote: “[A] dangerous ambition more often lurks behind the specious mask of zeal for the rights of the people, than under the forbidding appearance of zeal for the firmness and efficiency of government. History will teach us, that the former has been found a much more certain road to despotism, than the latter, and that of those men who have overturned the liberties of republics the greatest number have begun their carreer [sic], by paying an obsequious court to the the people, commencing Demagogues and ending Tyrants.” This is important to understand about Hamilton and the Federalists who largely governed the country for the first quarter century or so after its founding: they opposed pure democracy, believing that the common people could be too easily manipulated by ambitious demagogues. What the country needed, the Federalists believed, were enlightened leaders of class and property with the wisdom and gravitas to guide the unruly populace. 
Jay’s first contribution to The Federalist, no. 2, argues that the states are already, geographically and culturally, one nation composed of one people, and that a more centrally-governed Union, as opposed to a loose confederation of states, is the only reasonable form of government under the circumstances. The long-term security and prosperity of the country depends upon it. Here at the founding, in the opposition between Federalists and Antifederalists, one sees that opposition between strong unionists and supporters of states’ rights that was to come to a head in the Civil War.  In great measure because of the Civil War, we think of the United States as a single entity—a Union—rather than a collection of states. But for most of the nineteenth century, the concept of Union was still evolving, and has its first great expression here in The Federalist.
 George W. Bush defines sovereignty (in the context of Indian tribal sovereignty): "Tribal sovereignty means that; it's sovereign. I mean, you're a — you've been given sovereignty, and you're viewed as a sovereign entity. And therefore the relationship between the federal government and tribes is one between sovereign entities.”
 Hamilton, like most of the Founders, was well-read in the classics, and here there may be an echo of Caesar’s speech in Sallust’s Catiline, as the Roman Senate deliberates about how to punish conspirators against the Roman state: “It becomes all men, Conscript Fathers, who deliberate on dubious matters, to be influenced neither by hatred, affection, anger, nor pity. The mind, when such feelings obstruct its view, cannot easily see what is right; nor has any human being consulted, at the same moment, his passions and his interest. When the mind is freely exerted, its reasoning is sound; but passion, if it gain possession of it, becomes its tyrant, and reason is powerless (51).”
 The story of the development of a more democratic political culture, most closely associated with the names Jefferson and Jackson, is well told by Sean Wilentz in his book The Rise of American Democracy (Norton 2005; 796 pp.). The influence of more democratic elements on the Constitutional Convention itself is explored in Woody Holton’s recent book, Unruly Americans, which was recently nominated for a National Book Award (and is available in hardcover at River City Books in Northfield).
 I’m concurrently reading a fascinating study of the opposing concepts of states’ rights and union in the first century of the history of the United States: Forrest McDonald, States’ Rights and the Union: Imperium in Imperio, 1776-1876 (University of Kansas Press 2000). Imperium in imperio is Latin for divided sovereignty, the idea that sovereignty can reside in both the federal government and in the states.