Sumay became a prosperous port town serving whalers and other sailors in the 1800s and the second most populous settlement on Guam after Hagåtña, the capital of the Spanish Mariana Islands.

[1] In June 1678, amid the Spanish-Chamorro Wars where Spain attempted to solidify control of the island, Governor Juan Antonio de Salas led a military column to Sumay and the nearby village of Orote, which were both considered hotbeds of anti-Spanish resistance, setting fire to homes.

In 1734, Governor Francisco de Cárdenas Pacheco opened up new anchorages in Apra Harbor to better protect ships from attack.

[4] After the American Capture of Guam in 1898, Sumay continued its existence as an economically important village in a strategic location on the island.

[1] On April 7, 1917, Marines from Sumay fired warning shots at a launch from SMS Cormoran, a German merchant raider that had been held in Apra Harbor for two years.

In 1922, dredged materials from the harbor were used to fill the coastline at Sumay and a seawall was constructed, meaning that the village no longer followed the shoreline.

[1] In response to budgetary pressures after the Wall Street crash of 1929 and a new mood of isolationism the U.S. decided to close the seaplane base at Sumay on February 23, 1931.

[1] In 1935, Pan American Airways established rights to use the former Marine Aviation facility and made Sumay a base for its China Clipper.

[11] Pan American also built Guam's first hotel in the village for its wealthy Clipper passengers in March 1936 with supplies brought by the SS North Haven.

[13] Governor George McMillin wrote, Enemy planes appeared from the direction of Saipan shortly after eight o'clock, and the first bombs were dropped on the Marine Reservation and vicinity at 0827.

[...] Considerable additional material damage was done at the Marine Reservation, Pan Air Installation, Standard Oil tanks (which were set on fire by bombs on Monday, [8] December)[14] The residents of Sumay had fled during the bombing, many to a ranch named Apla at the current location of the Navy Exchange and Commissary.

In 1945, the U.S. military gave the Sumay residents in Apla two resettlement options: to Agat or to a "temporary" refugee camp in the nearby hills of what is now Sånta Rita-Sumai, originally called just Santa Rita.

Sumay residents were allowed back to their old village for the first time in 1961 to tend the graves of their relatives on All Souls' Day, a traditional Chamorro practice.