As we know during the spanish civil warr Franco tried to take Madrid in november of 1936, but after capturing part of the city the attack bogged down, and so the war continued until 1939
But what if he commited more reserves to it or the Republicans did some stupid move that allowed Madrid to be captured still in 1936, and the war ended in early 1937, how would this change the situation of spain? The first thing that comes in my head is that it wouldn't take so much time to rebuild it
In fact, Republicans were very lucky in the defense of Madrid because a car Italian tank that was lost in the Casa de Campo was put out of action and Republican troops, inspecting it, they found a copy of the plan general of the Nationalists for conquer Madrid. Then the General Miaja and then Lieutenant Colonel Rojo reorganized Republican defense plans after that stroke of luck (Republicans also were lucky when, at the time it seemed that the Nationalists had succeeded in breaking the front in Madrid's University City, General Miaja visited the area and prepared to fight personally there, haranguing the soldiers to die with him to defend Madrid -after taking his gun, he said them "Cowards, go back to your trenches. Die with your general!"-, which raised the morale of his soldiers and preventing the Nationalist entry.
If it had not happened, it is very likely that Madrid was conquered by the Nationalists. However, the Republican government had already fled to Valencia, and had ordered the defenders of Madrid that if the capital were indefensible, Republican forces should withdraw to Cuenca to establish a defensive line in place as directed by the Chief of the Army General of the Centre.
That is, the Nationalist capture of Madrid would not have meaning the end of the SCW, but probably shorten significantly it (probably would have ended before it began the year 1938), may occur the lifting of the Republican siege to the Nationalists refugees at the Shrine of Our Lady of Cabeza in Andujar (Jaen province) -the besieged endured since the September 14, 1936 until May 1, 1937, when the leader the besieged. the Civil Guard Captain Santiago Cortes, was badly wounded and the few beleaguered surrender to the Republicans-, becoming a stronger propaganda coup that liberation of the Alcazar of Toledo -which lasted from July 21 until September 27-.