As a legislator, Breckinridge secured the passage of a more humane criminal code which abolished capital punishment for all offenses except first-degree murder.

Called the father of the resultant constitution, he emerged from the convention as the acknowledged leader of the state's Democratic-Republican Party and fellow delegates elected him as speaker of the Kentucky House of Representatives in 1799 and 1800.

[3][note 2] A veteran of the French and Indian War, Robert Breckenridge had farmed as well as served first as Augusta County's under-sheriff, then as sheriff, then justice of the peace.

[1] Soon after John Breckinridge's birth, the family moved southward along the Wilderness Road to Botetourt County where Robert Breckenridge farmed, as well as became a constable and justice of the peace, and served in the Virginia militia.

[5] Breckinridge received a private education suitable to his class, possibly including Augusta Academy (now Washington and Lee University), but any records containing this information have been lost.

[11][12] If Breckinridge served, Harrison speculates that such occurred in one or two short 1780 militia campaigns supporting Nathanael Greene's army in southwest Virginia.

[19] The House adjourned June 28, 1783, and Breckinridge returned to the William and Mary College, studying through the end of the year, excepting the legislative session in November and December.

[23][24] As a Virginia legislator, Breckinridge served on the prestigious committees on Propositions and Grievances, Courts of Justice, Religion, and Investigation of the Land Offices.

[30] Polly, Cabell, and Letitia all fell ill but survived a smallpox epidemic in 1793; however, Mary Hopkins and their first son named Robert died.

[34] Alfred Grayson died in 1808, and in 1816, the widowed Letitia married Peter Buell Porter, who would later serve as Secretary of War under President John Quincy Adams.

[37] He believed changes were needed to the Articles of Confederation and agreed with much of the proposed U.S. constitution, but he did not support equal representation of the states in the Senate nor the federal judiciary.

[55] Although alarmed that frontier settlers might initiate war with Spain, President George Washington made no immediate attempt to obtain use of the Mississippi, which the society maintained was "the natural right of the citizens of this Commonwealth".

[52] In mid-1795, he, Robert Barr, Elijah Craig, and Harry Toulmin formed a committee to raise funds for a road connecting the Cumberland Gap to central Kentucky.

[59] Conservatives on the board and in the Kentucky General Assembly forced Toulmin – a liberal Unitarian – to resign in 1796, and Breckinridge's enthusiasm for his trusteeship waned.

[68] Breckinridge pressed to reform the state's criminal code, which was based on the English system and imposed the death penalty for over 200 different crimes.

[69] Inspired by Thomas Jefferson's failed attempt to reform Virginia's code, he first asked the Lexington Democratic Society to study ways to make punishments more proportional to crimes in November 1793.

[79] Breckinridge, chosen Speaker of the Kentucky House of Representatives at the outset of the 1799 session, took on the task, drafting resolutions reasserting the original principles and endorsing nullification.

[86] The largest group of delegates at the convention – about 18 in number – were aristocrats who advocated protection of their wealth and status, including instituting voice voting in the legislature (which left legislators vulnerable to intimidation), safeguarding slavery, and limiting the power of the electorate.

[33][86] A smaller group led by Green Clay and Robert Johnson consisted mostly of planters who opposed most limits on the power of the legislature, which they believed was superior to the executive and judicial branches.

[86] A third group, led by future governor John Adair, agreed with the notion of legislative supremacy, but opposed limits on other branches of the government.

[86] Legislative apportionment based on population, the addition of a lieutenant governor, and voice voting of the legislature – all issues advocated by Breckinridge – were also adopted.

[94][96] In one last attempt to derail the legislation in debate, Federalists argued that the judiciary would strike down the repeal as unconstitutional; Breckinridge denied the notion that the courts had the power to invalidate an act of Congress.

[94] Breckinridge advocated internal improvements and formed a coalition of legislators from South Carolina, Georgia, Tennessee and Kentucky to support a system of roads connecting the Southern coastal states with the western frontier, but the routes they proposed proved impossible to construct with the technology available at the time.

[98] Cognizant of Jefferson's desire for more time, Breckinridge offered a substitute resolution on February 23, 1803, allocating 80,000 troops and unlimited funds for the potential invasion of New Orleans, but he left their use at the discretion of the president.

[107] The June 29, 1804, edition of Philadelphia's Independent Gazetteer carried an editorial, signed "True American", that denounced the Virginia–New York coalition, attacked Clinton as too old, and called for electors to vote for Breckinridge for vice president.

[116] Other business in the session included creating a special fund that would allow Jefferson to recover the USS Philadelphia, which had been captured off the coast of northern Africa, and the repeal of the Bankruptcy Act of 1800; Breckinridge supported the passage of both measures.

[118] Robert Wright's measure adjourning Congress to Baltimore, Maryland, in protest of legislators' poor accommodations in Washington, D.C., was defeated by a vote of 9–19, but Breckinridge considered the issue of moving the U.S. capital worthy of further study.

[126] His most notable advisory opinion – that no local government in the Territory of Orleans had the power to tax federal property there – was upheld in the Supreme Court by Chief Justice John Marshall in McCulloch v.

[128] Cases such as Maley v. Shattuck involved international maritime law – an area with which Breckinridge was not familiar – and arose from the Napoleonic Wars, which complicated neutral American trade with both Britain and France.

[135] His daughter, Mary Ann, and her husband, David Castleman, inherited the horse and mule breeding operations, which eventually became the thoroughbred stable of Castleton Lyons.