During his father's presidency, López maintained a low profile in politics and instead focused on becoming a university professor at the Universidad del Rosario.

During this time, his fellow councilmen included two other politicians who went on to become key political players in the country, Álvaro Gómez Hurtado and future president Julio César Turbay Ayala.

This same year López traveled to the city of Valledupar after being appointed by President Carlos Lleras Restrepo as the first governor of Cesar Department, a newly created province in the northern Caribbean Region of Colombia.

In his speech he also promised to reduce the growing gap between farmer and urban populations and to fight poverty, messages that attracted the support of many left-wing political movements.

[2] Early support for his policies soon turned to fierce opposition, as many of his campaign promises, in particular those to make deals with unions and in the improvement of potable water access, went unfulfilled, and as subsidies were eliminated and inflation rose.

Unions and other leftist activists had been accumulating frustration and resentment for decades after the killing of Jorge Eliécer Gaitán, and the subsequent violence, and the hope for a more open society that came with Lopez's election turned into feelings of betrayal.

The López administration took a hard approach towards the planned strike, calling it subversive and at some point threatening arrest and forbidding public meetings.

[3] This only enraged the participants, and the major unionists were joined by teachers, students, independent workers, housewives, guerrilla leaders, and even members of the opposition conservative party.

The organizing committee demanded among other things salary increases, frozen prices for essential goods and public services fees, re-establishment of the right to meet and strike, and a reduction in work hours.

Major roads were blocked all over Bogota, and in many other cities around the country, and very soon many small skirmishes between protesters and riot police started occurring all over.