Let me begin telling you that I am actually spanish and my perspective has been built over the years and it is not "casual". Anyways, you asked how did it "come about", so... how did it begin?

14th april 1931 2nd spanish republic is proclamed after a regional elections: republican parties wins, because the spanish king Alfonso XIII was really bad considered, as he praised the dictatorship of Primo de Rivera. Anyways, this republic is not fully legitimate: some people in the right (and the pro-monarchy parties) consider it illegal. First goverment of the Republic is "slight-left". But anarchism and socialism is so strong in Spain that there are strong demonstrations and factories are taken over. Especially when in 1934 Alejandro Lerroux (right) gets the government with some CEDA (strong right) people in the government. 1936, politics are polarized: strong right vs. strong left, but the government of Lerroux's been involved in corruption: the Popular Front wins the ellection: a strong left party (not exactly revolutionary/communist) but hard-left.

Just after this elections, some spanish generals "afraid of communism" make a coup d'etat, and try to take over the country. It fails. But it starts a civil war that will last 3 years. The rebel side gets eventually to win the war, placing General's Franco as "Generalísimo". (i could write a whole bible about the civil war itself).

Important points: the civil war is considered by the Catholic Church as a "national crusade". That is an important reason why a) hard left people today still hate really strong the church b) church got a lot of power during the dictatorship.

To answer another of your points: Children were taken away from their parents in 2 kind of sitouations: a) children from republican side in the war were forgotten: their parents were killed and they were left apart. b) strong evidence supports that children were "stolen" in hospitals by priests and "nuns". That second thing kept happening untli not so long ago. There are still today ONG's that intend to gather families and children.

And no. They werent. Statues are still today in Madrid. There is a arc of triumph called "arco de la Victoria": celebrating the day the war was "won" by those in Franco's side. Still today it is a problem

There is a law (la ley de memoria histórica) which prohibits some of these statues to be removed.

You can keep asking me anything. I will answer. Just understand that this was harsh for us spanish people. And this is still today a problematic issue.

Thanks.