input: After Villa successfully captured the strategic prize of Torreon, Carranza ordered Villa to break off action south of Torreon and instead to divert to attack Saltillo. He threatened to cut off Villa's coal supply, immobilizing his supply trains, if he did not comply. This was widely seen as an attempt by Carranza to divert Villa from a direct assault on Mexico City in order to allow Carranza's forces under Alvaro Obregon, driving in from the west via Guadalajara, to take the capital first. This was an expensive and disruptive diversion for the Division del Norte. Villa's enlisted men were not unpaid volunteers but paid soldiers, earning the then enormous sum of one peso per day. Each day of delay cost thousands of pesos.  Disgusted but having no practical alternative, Villa complied with Carranza's order and captured the less important city of Saltillo, and then offered his resignation. Felipe Angeles and the rest of Villa's staff officers argued for Villa to withdraw his resignation, defy Carranza's orders, and proceed to attack Zacatecas, a strategic railroad station heavily defended by Federal troops and considered nearly impregnable. Since the colonial era, Zacatecas was the source of much of Mexico's silver, and thus a supply of funds for whoever held it. Villa accepted his staff's advice and cancelled his resignation, and the Division del Norte defied Carranza and attacked Zacatecas. Attacking up steep slopes, the Division del Norte defeated the Federals in the Toma de Zacatecas (Taking of Zacatecas), the single bloodiest battle of the Revolution, with Federal casualties numbering approximately 7,000 dead and 5,000 wounded, and unknown numbers of civilian casualties. (A memorial to and museum of the Toma de Zacatecas is on the Cerro de la Bufa, a key defense point where the Federal Army was entrenched.)  Villa's victory at Zacatecas in June 1914 broke the back of the Huerta regime. Huerta left the country on 14 July 1914. The Federal Army collapsed, ceasing to exist as an institution. In August 1914, Carranza and his revolutionary army entered Mexico City ahead of Villa. Civil war between the winners was the next stage of the Revolution.

Answer this question "Which battle was this?"
output: Toma de Zacatecas (Taking of Zacatecas),

input: From 1936, Ellington began to make recordings with smaller groups (sextets, octets, and nonets) drawn from his then-15-man orchestra and he composed pieces intended to feature a specific instrumentalist, as with "Jeep's Blues" for Johnny Hodges, "Yearning for Love" for Lawrence Brown, "Trumpet in Spades" for Rex Stewart, "Echoes of Harlem" for Cootie Williams and "Clarinet Lament" for Barney Bigard. In 1937, Ellington returned to the Cotton Club which had relocated to the mid-town Theater District. In the summer of that year, his father died, and due to many expenses, Ellington's finances were tight, although his situation improved the following year.  After leaving agent Irving Mills, he signed on with the William Morris Agency. Mills though continued to record Ellington. After only a year, his Master and Variety labels, the small groups had recorded for the latter, collapsed in late 1937, Mills placed Ellington back on Brunswick and those small group units on Vocalion through to 1940. Well known sides continued to be recorded, "Caravan" in 1937, and "I Let a Song Go Out of My Heart" the following year.  Billy Strayhorn, originally hired as a lyricist, began his association with Ellington in 1939. Nicknamed "Swee' Pea" for his mild manner, Strayhorn soon became a vital member of the Ellington organization. Ellington showed great fondness for Strayhorn and never failed to speak glowingly of the man and their collaborative working relationship, "my right arm, my left arm, all the eyes in the back of my head, my brain waves in his head, and his in mine". Strayhorn, with his training in classical music, not only contributed his original lyrics and music, but also arranged and polished many of Ellington's works, becoming a second Ellington or "Duke's doppelganger". It was not uncommon for Strayhorn to fill in for Duke, whether in conducting or rehearsing the band, playing the piano, on stage, and in the recording studio. The 1930s ended with a very successful European tour just as World War II loomed in Europe.

Answer this question "Did he retire during this time?"
output: