Alexander Hamilton entered public life as a writer supporting American resistance to Britain, then served as an artillery officer in the Revolutionary War. Work on George Washington's staff from 1777 brought responsibility for correspondence and military administration as well as political observation. He later obtained field command and led an assault at Yorktown in 1781. War convinced him that national institutions and reliable finance were needed beyond state cooperation.

After the war he practised law in New York, helped establish the Bank of New York and served in the Confederation Congress. The Annapolis Convention of 1786 became a step toward the broader constitutional meeting the following year. Hamilton advocated strong central authority at Philadelphia, although many of his preferences did not prevail. He then wrote most of the Federalist essays with James Madison and John Jay and played an important role in New York's ratification. The essays defended the adopted Constitution, not every proposal he personally favoured.

As the first treasury secretary from 1789 to 1795, Hamilton developed plans to fund debt, assume state obligations and establish a national bank. Customs, excise revenue and administrative organization gave the government practical capacity. His Report on Manufactures advocated measures to encourage economic development. Opponents challenged the distribution of benefits, the relationship with financiers and his interpretation of implied constitutional powers. The Whiskey Rebellion exposed resistance to federal taxation. Conflict with Jefferson and Madison helped produce durable party divisions, while his influence on Washington's foreign policy supported neutrality and the settlement with Britain known as Jay's Treaty.

Hamilton continued shaping Federalist politics after leaving the cabinet. Military preparations during the crisis with France and conflict within the party heightened rivalry with John Adams. Publication of the Reynolds affair defended him against allegations of public financial misconduct but damaged his personal reputation. In the disputed election of 1800 he preferred Jefferson to Aaron Burr despite longstanding policy differences. Further attacks on Burr's character contributed to the challenge ending in their duel in July 1804; Hamilton died from his wound the next day. He strengthened federal finance and administration while intensifying disputes about power and the interests government should serve.