On 1 April 1902, 3 KAR moved its headquarters from Mombasa to Nairobi, and together with 4 KAR and 5 KAR, was used by the British colonial government in expeditions against those who resisted British rule. In 1904 5 KAR, which was mainly made up of Indian troops, was disbanded chiefly because of maintenance costs and also because the British felt they had contained the resistance to their rule. It was however reconstituted in 1916 during World War I and stationed in Meru.
Later in 1926, 5 KAR was again disbanded and their colours were handed over to 3 KAR for safe custody. On 1 March 1930 the unit was once again reconstituted, presented with their colours and stationed in Nairobi. After World War II both battalions were used by the colonial government to contain the Mau Mau rebellion. On the dawn of independence the Kenya National Assembly passed a bill (Kenya Bills 1963) to amend the status of the military forces in Kenya .
Accordingly, the former units of the King's African Rifles were transformed to the Kenyan Military Forces and the Independent Kenyan Government was legally empowered to assign names to the units as deemed necessary with effect from midnight, 12 December 1963. Thus 3 KAR, 5 KAR, and 11 KAR became 3 Kenya Rifles, 5 Kenya Rifles, and 11 Kenya Rifles respectively. The transformation of King's African Rifles to Kenya Military Forces on the midnight of 12 December 1963 was a major milestone in the foundation of today's Kenya Army units.
Kingman Reef was discovered by the American Captain Edmund Fanning of the ship Betsey on June 14, 1798. Captain W. E. Kingman (whose name the island bears) described it on November 29, 1853. Kingman Reef was claimed in 1860 by the United States Guano Company, under the name "Danger Reef". This claim was made under by the Guano Islands Act of 1856 although there is no evidence that guano existed or was ever mined on Kingman Reef.
Lorrin A. Thurston formally annexed Kingman to the United States on May 10, 1922, by reading this declaration on shore:
Be it known to all people: That on the tenth of May, A.D. 1922, the undersigned agent of the Island of Palmyra Copra Co., Ltd., landed from the motorship Palmyra doth, on this tenth day of May, A.D. 1922, take formal possession of this island, called Kingman Reef, situated in longitude 162 degrees 18' west and 6 degrees 23' north, on behalf of the United States of America and claim the same for said company.
On December 29, 1934, the US Navy assumed jurisdiction over Kingman Reef. The lagoon was used in 1937 and 1938 as a halfway station between Hawai'i and American Samoa by Pan American Airways flying boats (Sikorsky S-42B). Pan Am wanted to expand flights into the Pacific and include Australia and New Zealand to their "Clipper" air routes. In 1935 it was decided that the lagoon at Kingman Reef was suitable for overnight stops en route from the U.S. to New Zealand via Samoa. Kingman Reef became the stopover to and from Pago Pago, American Samoa, located 1,600 miles (2,600 km) further south. A supply ship, the North Wind, was stationed at Kingman Reef to provide fuel, lodging, and meals. The S42B Pan American Clipper II, piloted by Captain Edwin Musick, landed at Kingman on its first flight on March 23, 1937. Several successful flights followed, but the flight on January 11, 1938 ended in tragedy. Shortly after the early morning take off from Pago Pago, bound for New Zealand, the Clipper exploded. The right outboard engine had developed an oil leak and the plane burst into flames while dumping fuel; there were no survivors. As a result of the tragedy, Pan Am ended flights to New Zealand via Kingman Reef and Pago Pago. A new route was established in July 1940 by way of Canton Island and New Caledonia.
On February 14, 1941, President Franklin Roosevelt issued Executive Order 8682 to create naval defenses areas in the central Pacific territories. The proclamation established "Kingman Reef Naval Defensive Sea Area" which encompassed the territorial waters between the extreme high-water marks and the three-mile marine boundaries surrounding the atoll. "Kingman Naval Airspace Reservation" was also established to restrict access to the airspace over the naval defense sea area. Only U.S. government ships and aircraft were permitted to enter the naval defense areas at Kingman Reef unless authorized by the Secretary of the Navy.