1901: The Platt Amendment withdraws American troops from Cuba but allows Cuban territory to be given to the United States.
1902: Americans invest heavily in Cuba, buying up 2/3rds of the sugar production, the majority of tobacco production, and turning most of the island into a first rate tourist destination. Anti-Discrimination acts of OTL are not passed yet. Tomas Estrada Palma (An American Citizen) is elected First President of Cuba in an uncontested campaign.
1906: Tomas Palma attempts to extend his presidency and a revolt breaks out. Both parties ask the United States to intervene. William Taft negotiates the peace treaty and Elihu Root assumes temporary governorship. He passes a very popular Anti-Discrimination act that requires a certain percentage of Cuban employment in businesses.
1909: Pro-American sentiment has skyrocketed and Statehood movements have arose from American businesses and Cubans who feel indebted to America for stopping their civil war and generally raising the quality of life. A referendum is held that gives Cubans the option of Becoming Fully Independent Again, Applying for American Statehood, or Maintaining the Status Quo. No option passes with a majority and the status quo is maintained. The Foraker Act was expanded to include Cuba, giving them a popularly elected representative in the US congress.
1913: The Jones-Shafroth Act is passed (And 4 years ahead of schedule!) giving Puerto Ricans and Cubans American Citizenship. However, the President of the United States still appoints the governor and cabinet. Protests erupt throughout the island, calling for greater representation.
1917: Cubans and Puerto Ricans are drafted into the army to serve in WW1, though few make it to the front lines.
1919: Returning veterans protest against the lack of elected representation and call for and get another referendum. The choices on the ballot are: Cuba applies for admission as a US State, Cuba becomes independent, Cuba becomes a commonwealth, or to maintain the status quo. Applying for admission barely passed the minimum, and it was added as a state later in the year.