what action by charles cotesworth pinckney made him a vice president candidate in 1800?

Charles Cotesworth Pinckney was not a candidate for Vice President in 1800, but rather a candidate for President. He was a Federalist and was nominated to run for the presidency as John Adams' running mate against the Democratic-Republican candidates Thomas Jefferson and Aaron Burr. However, at that time, the electoral system did not differentiate between presidential and vice-presidential candidates in terms of votes cast by the Electoral College.

Pinckney's reputation that made him a suitable candidate for the presidency was built on his significant contributions as a statesman, soldier, and diplomat. One of his notable actions was his participation in the XYZ Affair in 1797, when he, along with John Marshall and Elbridge Gerry, were sent to France to negotiate with the French government to resolve issues stemming from the Jay Treaty with Britain. French agents, referred to as X, Y, and Z in documents released to the public, demanded bribes before negotiations would begin. Pinckney's alleged response, "No! No! Not a sixpence!" earned him national acclaim for his patriotism and steadfastness, enhancing his reputation and helping to solidify his position as a Federalist candidate in the 1800 election.

Despite his strong Federalist credentials, Pinckney and Adams were defeated by Jefferson and Burr, who each received an equal number of electoral votes, leading to a contingent election in the House of Representatives where Thomas Jefferson was eventually chosen as President. The election of 1800 later resulted in the passage of the 12th Amendment to the U.S. Constitution, which provided a separate electoral vote for President and Vice President.