The party, which believed in Puerto Rican independence, was led by Muñoz Rivera as president, with Barceló as the secretary general.

[7] In 1910, Barceló founded the Association of Puerto Rico, with the idea of protecting the main industries of the island, which at that time were coffee, tobacco and sugar, against imported brands.

[6] In 1914, Barceló, Muñoz Rivera and de Diego were members of an executive council that tried to form an alliance between the Union and Republican Parties.

[7] Barceló opposed the Jones-Shafroth Act, which granted United States citizenship to residents of Puerto Rico, because he thought it might interfere with gaining independence.

[5] The Jones-Shafroth Act was approved by the United States and signed into law by President Woodrow Wilson on March 2, 1917.

The Union Party under Barceló's leadership resolved to adopt a different stance and to seek more autonomy, which he believed would finally lead to independence.

[5] In 1921, President Warren G. Harding appointed Emmet Montgomery Reily, who was a strong supporter of "Americanism", as Governor of Puerto Rico.

Reily was an extremely unpopular governor, he was the subject of corruption allegations and an investigation by Puerto Rican local officials.

He played an instrumental role in what resulted in the construction of buildings for the University of Puerto Rico and the development of an excellent native faculty.

[5][8] Both Barceló and Jose Tous Soto, the president of the pro-statehood Republican Party of Puerto Rico, understood by Taft's statement that neither independence nor statehood would be considered for the time being.

Georgetti believed in the original ideal of the Union Party and that the "Alliance" coalition would not work because of their ideological differences.

[9] Differences became apparent between Barceló and Tous Soto and Félix Córdova Dávila, the Resident Commissioner of Puerto Rico in Washington, as to the goals of the alliance.

Barceló requested that Herbert Hoover, the newly elected President of the United States, retain Horace Towner temporarily as governor of the island.

Hoover, however, consulted Córdova Dávila, instead of Barceló, in regard to his intentions of naming Theodore Roosevelt Jr. to the position.

Eventually, Muñoz Marín, who had different points of view as to how Puerto Rico should go about obtaining its independence, would collide with Barceló.

Following the Río Piedras massacre in 1935, US Senator Millard Tydings in 1936 introduced a bill in Congress for Puerto Rican independence.

[12] Barceló was responsible for the approval of many laws which led to reforms and that would greatly benefit the social justice, labor and the Puerto Rican economy.

Barceló helped to establish the minimum wage rate, workers' compensation and limited working hours.

Barceló, also played a principal role in the establishment of "The School of Tropical Medicine", "The Federal Penitentiary", "The Antituberculosis Sanctuary" and numerous other centers.