He became involved in politics, and played an active role in three of the ten statehood conventions that secured the separation of Kentucky from Virginia in 1792.

He became one of the state's first representatives, and served in the Kentucky General Assembly before being elected governor in a race where, due to his immense popularity, he ran unopposed.

Greenup's term in office was marred by accusations that he had participated in the Burr Conspiracy to align Kentucky with Spain prior to the former's separation from Virginia, but he vigorously and successfully rebutted these charges.

[1][2][3] During the American Revolutionary War, he served in Grayson's Additional Continental Regiment as a lieutenant, and may have seen action at Brandywine and Germantown.

[4] In 1781, Greenup helped settle the area now known as Lincoln County, Kentucky where he spent time as a surveyor and a land speculator.

[6] Following Virginia's creation of Kentucky County in 1783, he was admitted to the bar of the district court of Harrodsburg and served as clerk from 1785 to 1792.

[6] During his service, he was appointed to a committee with Benjamin Logan and James Garrard to make recommendations on ways to further divide the area that would become Kentucky.

Everman, biographer of fellow delegate James Garrard, noted that despite Greenup's excellent legal background and legislative experience, his lack of oratorical skills prevented him from taking more of a leadership role in the conventions.

[12] Greenup was a candidate for governor of Kentucky in 1800, but was runner-up to James Garrard in a four-man race that also included Benjamin Logan and Thomas Todd.

[12] A partisan Frankfort newspaper implicated Greenup in the Burr conspiracy, but he successfully defended himself and preserved his reputation.

[12] Following his term as governor, Greenup was chosen as a presidential elector for the ticket of James Madison and George Clinton.

[17] Greenup died April 27, 1818, at Blue Lick Springs Resort, where he had traveled seeking relief from his rheumatism.