The Spanish-American War was a conflict in 1898 between Spain and the United States, effectively the result of American intervention in the ongoing Cuban War of Independence.
William McKinley was president of the United States, and the causal event was the explosion of the battleship USS Maine in Havana Harbor, Cuba on February 15, 1898.
So, what does that have to do with Hawai‘i?
Well, back then, Spain had interests in the Pacific, particularly in the Guam and Philippines. Although the main issue was Cuban independence, the ten-week war was fought in both the Caribbean and the Pacific.
Likewise, US foreign policy advocated the taking of the Caribbean Islands and the Philippine Islands for bases to protect US commerce.
Meanwhile, Hawai'i, had gained strategic importance because of its geographical position in the Pacific. Honolulu served as a stopover point for the forces heading to the Philippines.
In July 1898, the joint 'Newlands Resolution' for annexation was adopted by Congress and signed by President McKinley. At the time, there was no assigned garrison here until August 15, 1898, when the 1st New York Volunteer Infantry regiment and the 3rd Battalion, 2nd US Volunteer Engineers landed in Honolulu for garrison duty.
The two commands were initially camped alongside each other as though they were one regiment in the large infield of the one-mile race track at Kapi‘olani Park. The initial camp in the infield at the race track was unnamed.
As more members of the regiment arrived, the camp was moved about three or four hundred yards from the race track to an area called ‘Irwin Tract.’ The Irwin Tract camp was named "Camp McKinley," in honor of the president.
The site “was near the only ocean-bathing beach on the Island and the reported site of a proposed Sanitarium selected by the resident physicians in the immediate vicinity of the best residential quarter of the Island. In addition it had shade in the park, a drill and parade ground on the racecourse, city water, and was accessible.”
The troops used the bathing facilities at the Sans Souci Resort which was located on the beach at the southeast corner of the park.
Camp Otis was a short-lived camp of Philippine expeditionary troops who arrived on the troop ship ‘Arizona’ on August 27, 1898 and were left in Honolulu when the ship went on to Manila.
The soldiers camped inside the racetrack at Kapi‘olani Park. The camp was later moved east within the racetrack to a point “nearly opposite Camp McKinley.” The camp was named after Major General Elwell S. Otis, US Volunteers, the commanding officer in the Philippines in 1898-99.
Camp Otis was abandoned about November 7, 1898 when the ‘Arizona’ returned and the troops departed for Manila.
Owing to the prevalence of malarial and typhoid fever, they moved the regiment to a camp to Wai‘alae, on the north side of Diamond Head, about three miles from “Camp McKinley.”
They temporarily occupied the Paul Isenberg estate which stretched from Kapahulu Avenue to Kāhala Beach. A letter from one soldier camped there noted, “The tents are pitched on the sandy beach at Waialie (sic)…”
The 2nd Engineers ultimately built barracks and other buildings for the new Camp McKinley just north of Kapi‘olani Park, between Leahi and Kana‘ina avenues (it is now covered by businesses along Kapahulu Avenue and residences in the area.)
Local hospitals were used for the sick soldiers until Independence Park Hospital was established on August 15, 1898. The Red Cross also established a hospital for soldiers in the Child Garden Building on Beretania Street in June, 1898.
The Independence Park Hospital was located in a dance pavilion at Independence Park, southeast of the corner of Sheridan and King Streets.
In October, 1898, concern over conditions at Independence Park Hospital and the large number of sick soldiers required that additional hospital space be obtained. The Independence Park Hospital was closed in January, 1899.
The Nu‘uanu Valley Military Hospital (also known as "Buena Vista Hospital") was located at the former John Paty home (known as Buena Vista) on the east side of Nu‘uanu Avenue at Wyllie Street. (That site is now covered by the Nu‘uanu-Pali
Highway interchange, just north of the Community Church of Honolulu.)
Camp McKinley remained in existence until Fort Shafter was opened in late June, 1907. The garrison was either artillery or coast artillery troops during this period.
The image shows the initial encampment in Kapi‘olani Park. In addition, I have included other images relates to Camp McKinley in a Folder of like name in the Photos section on my Facebook page.