The first administration of Alfonso López Pumarejo (1934-8) known as the "revolución en marcha", has proven an enduring theme of historical interest.

[2] He was elected president in 1934 almost unopposed, and as the second participant of the so-called Liberal Hegemony in Colombia, his initial government platform became known under the name "Revolución en Marcha" (Marching Revolution), as it attempted to implement far reaching social and political reforms.

These actions earned López Pumarejo the backing of important rural and labour sectors, in addition to that of the Colombian Communist Party, but they likewise divided his previous political allies, some of which called for moderation.

After being re-elected in 1942, the second administration of López Pumarejo faced a stronger opposition in Congress and by both the more conservative and more radical sectors within the president's own Colombian Liberal Party which resulted in the interruption of previous reforms.

After his return to the country, further political conflicts led to a failed military coup attempt in 1944, and López Pumarejo finally resigned in early 1945.