What country entered revolutionary war as a french ally in 1779

Spain

Explanation:

The Anglo-Spanish War of 1779-1783, part of the War of Independence of the United States, was the conflict between Spain and Great Britain for Spanish intervention in favor of the United States. Spain, allied with France through the Family Pacts, saw the Revolution of the Thirteen Colonies as an opportunity to weaken the British Empire, which had caused major losses during the Seven Years War. Spain began to participate in the conflict from 1776 with financing, along with France.

declare war, appoint military officers, sign treaties, make alliances