I'll take your second question first. The East German government, under Walter Ulbricht, officially called the Berlin Wall der antifaschistischer Schutzwall ("Anti-Fascist Protective Barrier"). When you remember that it was common for Eastern-Bloc politicians to casually refer to the capitalist west as "fascist," this accurately sums up the Ulbricht regime's justification for building the Wall: It was necessary to protect the GDR from the West. This was framed not merely in terms of military protection and counter-espionage, but also economic and demographic self-preservation.

In the years before the erection of the Wall, the GDR hemorrhaged capital, both human and economic. Lured by the Wirtschaftswunder ("Economic Miracle") of the Federal Republic and West Berlin in the 1950s, and the strength of western currency, several million East Germans committed Republikflucht ("Desertion of the Republic"), fleeing to West Berlin or West Germany. Many of these refugees were young, educated, and skilled - precisely the sort of people that East Germany needed to stay. The unguarded border between East and West Berlin made such desertion exceedingly easy: One had, in many cases, only to walk across the street and report to the West Berlin authorities. This became the only widely available method of flight after 1952, when the East German government sealed the German-German border. In Berlin, traffic across the sector boundaries was an everyday reality. Many resident East Berliners held jobs or studied in West Berlin. West Berliners, for their part, would often cross into East Berlin for cheap shopping, since their Western Deutsche Mark was worth so much more than the Eastern Mark.

The Ulbricht regime - not without reason - understood this situation to be a lethal threat to the survival of the GDR. His presentation of the problem, both to the broader public and to the GDR's Eastern Bloc allies, was a mix of truth and lies. He talked about the out-flow of goods due to commerce in Berlin, and of the "trade in people" - a less-than-convincing attempt to portray the refugees as kidnapping victims, when they were not being portrayed as venal traitors who stole an upbringing from the GDR before fleeing it for pecuniary reward in the West. Building the Wall, from this perspective, was like cauterizing a wound. And a similar medical analogy was deployed by Ulbricht himself. He justified the wall by describing the sort of people it was intended to hinder in an August 28, 1961 article in Neues Deutschland, the official paper of the ruling Socialist Unity Party of East Germany: "Counter-revolutionary vermin, spies and saboteurs, profiteers and human traffickers, spoiled teenage hooligans and other enemies of the people's democratic order [who] have been sucking on our Workers' and Peasants' Republic like leeches and bugs on a healthy body."

The people of East Berlin reacted in much the same way as the people of West Berlin, though their reactions were understandably more muted. First, there is reason to believe that they understood even in advance of the Wall's rise that it was coming. In the days and weeks before the border closure, the number of refugees reporting to West Berlin's processing centers rose dramatically. This was, in part, spurred on by the East German government itself. On June 15, 1961, Ulbricht famously declared at a press conference that "no one has the intention of building a wall." ("Niemand hat die Absicht, eine Mauer zu errichten.") It has long been speculated that this statement was a dog-whistle to the people of Berlin, indicating that the East German government definitely intended to build a wall. Ulbricht's play here was to force the hand of the Khrushchev government in Moscow, which had opposed the building of a wall, by inciting more East Germans to cross the border, rendering the border situation even more unstable and untenable.

After the border was actually sealed on August 13, 1961, there were some dramatic scenes in along the border as East Berliners attempted last-minute flights into the West. Nurse Ida Siekmann became the first casualty of the Wall on August 23, when she jumped from her window on the Bernauer Straße - the front facade of her apartment building was the border between the Soviet and French sectors - to her death on the pavement below. Others successfully dodged through gaps in the barbed wire that, initially, was all that constituted the "Wall." Groups of East Berliners observed the construction mostly from afar, since the builders were guarded by Volkspolizei and Kampfgruppen der Arbeiterklasse ("Combat Groups of the Working Class" - East German paramilitaries). Some of those crowds became vocal in their disgust and anger, but this came to little and was never as open or virulent as the activity of enraged West Berliners on the other side. There was certainly no repetition of the June 1953 strikes and protests that had so nearly toppled the Ulbricht government.

In the ensuing years, many attempts were made to rush through, slip past, tunnel under, or fly over the Wall, but there was no organized, massive attempt on the part of East Berliners to protest or damage the Wall or its protectors. Whether this was a function of the repression of the East German government, self-control and acceptance on the part of the East German people, or genuine enthusiasm for the Anti-Fascist Barrier is hard to say. It was likely a combination of these factors, in grossly unequal proportions. Especially after the initial shock of the separation wore off, Berliners on both sides of the Wall acclimated to its existence in many ways. Whatever the proportion of acceptance to enthusiasm in the 1960s, how much popular support for the Wall remained by the end of the Cold War was clearly demonstrated by the crowds who cheered its fall to the echo in November of 1989.