The 1917 Humacao Senate elections, both part of the first elections under the Jones-Shaffroth Act and the first Senate elections period resulted in the election of Unión Party Leader, and Grandfather to future Pro-Statehood Governor Carlos Romero Barceló, Antonio R. Barceló.
Unlike his more famous Grandson, Antonio Barceló was an ardent supported of Autonomy and independence, attaining alongside his Seat-mate Jose J. Benítez Díaz 51.89%, with the Pro Statehood Partido Socialista and Jose Celso Barbosa's Partido Republicano at second and third respectively.
While the Partido Unión won due to their pluralities in most of the district and Strong majorities in the Caguas Suburbs of Gurabo, Juncos, and San Lorenzo, The Partido Socialista's Strength in the sugar producing sections of the District brought them into a distant second.
It should also be mentioned that the lack of urban machines is what resulted in the partido Republicano comming in third, with only Gurabo, San Lorenzo, and Juncos' Urban machines allowing los Republicanos to take Second.