In 1865, the board of education adopted a policy of separating school children by sex, and the Town Free School became the Mililani Girls School. (Town Free School was successor of Oʻahu Charity School – the first English-language-focused school.) Most of the boys were sent to the Royal School.
In 1873, the Fort Street School went public, and in 1895 was split to create Kaʻiulani Elementary and the islands’ first public high school - Honolulu High School. The high school moved near Thomas Square and it was renamed President William McKinley High School; the building served that function until the present McKinley High was erected in 1923. At that time, the old school was renamed Linekona (Lincoln) Elementary; it was the main elementary school in Honolulu.