number of distinguished candidates appeared, including Buenos Aires Governor Dardo Rocha and Foreign Minister Bernardo de Irigoyen. Roca tolerated no opposition against his dauphin, however, who was selected nearly unanimously on April 3, 1886. 1892 An 1888 massacre of a May Day gathering and an unprecedented financial crisis led to the formation of the first meaningful opposition to develop as reform movements in urban areas, culminating in the Revolution of the Park that forced Juárez Celman's 1890 resignation. These developments gathered speed when the Civic Youth Union became the Radical Civic Union (UCR), in 1891. Instability also prompted moderates from within the PAN to advance a diplomat, Roque Sáenz Peña, as the nominee. Roca foiled this move by persuading former Supreme Court Chief Justice Luis Sáenz Peña (Roque's father) to run - forcing the young reformist to withdraw. The UCR's appeal, for its part, helped lead President Carlos Pellegrini (who replaced the besieged Juárez Celman) to declare a state of siege a week before the April 10, 1892, elections. The resulting UCR electoral boycott left the ruling PAN as the only party on the ballot, handing its nominee the presidency unanimously. 1898 Having obtained the aging Luis Sáenz Peña's resignation in favor of Vice President José Evaristo Uriburu (who was good stead with both Roca and Mitre), Roca once again carried the PAN standard in 1898. The UCR, which had lost its founder, Leandro Alem, to suicide in 1896, was divided between those who backed Senator Bernardo de Irigoyen's drive to form coalitions with more conservative parties, and those who supported the party's new leader, Hipólito Yrigoyen (who boycotted this and future "election songs" - establishing what later became known as the UCR's "break before bending" policy). Public debate was heated on the eve of the January 30 elections to a constitutional assembly entrusted to increase the number of congressmen and cabinet members, as well before the April 10, 1898, general election. The electoral college yielded no surprises, though, and Roca was returned to the presidency. 1904 Riding high after another term of prosperity and important diplomatic accomplishments such as the May 1902 Pact with neighboring Chile over a border dispute and Foreign Minister Luis Drago's settlement of imminent war between the German Empire and Venezuela, President Roca enlisted Congressman Manuel Quintana as the PAN standard bearer. Within the PAN itself, some dissent was evident over Roca's dominance. These voices