Sumido is a barrio in the municipality of Cayey, Puerto Rico. Its population in 2010 was 802. Sumido was in Spain's gazetteers until Puerto Rico was ceded by Spain in the aftermath of the Spanish–American War under the terms of the Treaty of Paris of 1898 and became an unincorporated territory of the United States. In 1899, the United States Department …Sumido is a barrio in the municipality of Cayey, Puerto Rico. Its population in 2010 was 802. Sumido was in Spain's gazetteers until Puerto Rico was ceded by Spain in the aftermath of the Spanish–American War under the terms of the Treaty of Paris of 1898 and became an unincorporated territory of the United States. In 1899, the United States Department of War conducted a census of Puerto Rico finding that the combined population of Sumido and Jájome Bajo barrios was 961.