He received high honors from many countries, including the Legion of Honor of France. On 4 July 1997, upon completion of the sesquicentennial of his birth, the Government of Costa Rica posthumously awarded the rank of Ambassador Emeritus. He wrote several important historical works and collections rich documentaries published. His major works include The Republic of Costa Rica, Costa Rica, Nicaragua and Panama in the sixteenth century, Costa Rica and Colombia from 1573 to 1581, its jurisdiction and territorial limits of the Panama Canal Nicaragua and Costa Rica in 1620 and 1887 Limits of Costa Rica and Colombia; History of the territorial jurisdiction of the Republic of Costa Rica, Costa Rica, the Mosquito Coast, Historical Atlas of the Republic of Costa Rica, and Veragua Mosquito Coast, territorial jurisdiction of the Republic of Costa Rica, El General Morazan and several poems and essays. He belonged to numerous academies and research companies and had close friendships with distinguished writers and intellectuals, including Juan Montalvo, Emilia Pardo Bazán and Rubén Darío . In 1883 sought and obtained the transfer in favor of the Marquis de Peralta, Holy Roman title granted in 1738 by Emperor Charles VI to his uncle's great great grandfather Juan Tomás de Peralta y Franco de Medina . It was the second and last owner of that noble dignity. He was declared a Hero of the Nation by the Congress of Costa Rica in 1919 and 1927 . He died in Paris, France, on 1 August 1930. His remains were brought to Costa Rica's capital and was buried there. The Diplomatic Institute of the Foreign Ministry of Costa Rica and an avenue in the city of San Jose are named after him. The Prize "Manuel Maria de Peralta" is a recognition given by the Costa Rican Association of International Law "Philip C. Jessup" (ACODI) annually to a distinguished Costa Rican for their contributions to international law, the International Policy and Diplomacy. The Prize has been awarded so far, in its fourteen editions to the following persons:  The Prize is named in reference to Manuel Maria de Peralta y Alfaro and the Foreign Service Institute "Manuel Maria de Peralta" the Ministry of Foreign Affairs and Worship of Costa Rica.