Question

Which early political party was led by Jefferson and Madison?

Answer 1

The Democratic-Republicans

Explanation:

Then Secretary of State Thomas Jefferson (who later became the 3rd President of the USA) and James Madison (who later became the 4th President of the USA) formed the 2nd US political party, the Democratic-Republican party, to oppose the Federalist party of then Secretary of the Treasury Alexander Hamilton (who later was shot and killed in a duel with Vice President Aaron Burr).

The Federalists were, in general, in favour of a strong central government whereas the D-R party was in favour of states' rights.

https://en.wikipedia.org/wiki/Democratic-Republican_Party
https://en.wikipedia.org/wiki/Burr%E2%80%93Hamilton_duel