The French ambassador who helped arrange the 1898 peace protocol between the United States and Spain was Jules Cambon.
Cambon was France’s ambassador to the United States when Spain authorized him to act on its behalf in peace discussions. He negotiated with U.S. Secretary of State William R. Day, and the two signed the Protocol of Peace in Washington on August 12, 1898.
The protocol suspended hostilities and set the framework for formal peace negotiations. It required Spain to evacuate Cuba and surrender control of Puerto Rico and Guam, while also establishing commissions to negotiate a final treaty.
The later Treaty of Paris, signed on December 10, 1898, formally ended the Spanish–American War. Cambon is sometimes confused with Paul Cambon, another prominent French diplomat, but Paul was not the ambassador who signed this U.S.–Spanish peace protocol.