two political organizations merged into the Puerto Rican Nationalist Party. In 1924, Dr. Pedro Albizu Campos joined the party and on May 11, 1930, Dr. Pedro Albizu Campos was elected president of the Puerto Rican Nationalist Party. On March 21, 1937, there was a peaceful civilian march that took place on Palm Sunday in Ponce, Puerto Rico. The police began shooting their firearms at those present and 19 civilians and two policemen were killed, The shootings by the police became known as the Ponce massacre. This event influenced her nationalistic views even further and she joined the New York cell of the Nationalist Party in 1937. Oscar Collazo In 1941, Oscar Collazo moved to New York City, which at the time had a large Puerto Rican community. There he met and married Rosa Cortez. The couple lived in an apartment building in the Bronx. They had a total of three daughters from previous marriages: Rosa had two and Oscar had one. Oscar, who worked in a metal polishing factory, joined the New York branch of the Puerto Rican Nationalist Party. He met and became friends with Albizu Campos when the latter was hospitalized for a time at the Columbus Hospital. Oscar was named Secretary of the New York branch of the Puerto Rican Nationalist Party and later served as its president. He met Griselio Torresola, a fellow nationalist, in New York and the two men soon became friends. Plot to assassinate President Truman On October 30, 1950, Torresola and Oscar learned that the Jayuya Uprising in Puerto Rico, led by the nationalist leader Blanca Canales, had failed. Torresola's sister had been wounded and his brother Elio was arrested. Believing they had to do something for their cause, Oscar and Torresola decided to assassinate President Harry S. Truman, in order to bring world attention to the need for independence in Puerto Rico. On October 31, 1950, Oscar and Torresola arrived at Union Station in Washington, D.C. and registered in the Harris Hotel. On November 1, 1950, with guns in hand, they attempted to enter the Blair House, where the President was living during renovation of the White House. During the attack, Torresola mortally wounded White House Police officer, Private Leslie Coffelt. Oscar wounded another man. After wounding others, Torresola was killed by the mortally wounded Coffelt. Oscar was shot in the chest and arrested. In 1952, Oscar was convicted and sentenced