The Americans waged a war against the Filipino government in Luzon but in Negros, the US forces were welcome and slowly the Americans imposed their will and the Negros Republic became irrelevant. The Americans offered and Negros accepted to be a civil province of the Philippines under American rule in 1901. The Negros Republic ceased to exist.
American capital expanded the sugar market, and new sugar mills producing centrifugal sugar were established throughout the island. By 1935, Negros was producing over a million tons of sugar, 90% of which was exported to the US. American sugar interests disadvantaged by the tariff free, cheap Philippine sugar demanded a reduction in volume for them to support Philippine independence. A quota system was imposed.
World War II broke out in the Philippines in 1941 and in May 1942, Japanese forces occupied Negros but over 80% of the Filipino troops waged guerilla warfare while the Americans surrendered. Liberation came in 1945 and Negros revived and expanded the sugar industry bringing wealth back, and more when the US imposed an embargo against Cuba in 1961. More mills were established so that progress and human, infrastructure, educational and religious development continue with new products and services spinning out of the sugar money.