The bridge is built on the former boundary of the city with its rural areas, where an excise wall was built in 1732. A wooden drawbridge was built as part of the wall; it served as a gate to the city. The name Oberbaumbrücke stemmed from the heavy tree trunk, covered in metal spikes, that was used as a boom to block the river at night to prevent smuggling.
In April 1945 the middle section of the bridge was blown up in an attempt to stop the Red Army from crossing it.
After the war ended, Berlin was divided into four sectors. The Oberbaum Bridge crossed between the American and Soviet sectors and so, when the Berlin Wall was built in 1961, the bridge became part of East Berlin's border with West Berlin. More recently, you may have seen the bridge often in the 1998 film Run Lola Run.
Regularly traversing the Oberbaumbrücke by train and car and bike brings me closer to the history of Berlin. My summer includes showing paintings for day on this bridge when it is briefly closed and then visited by 30,000 people at the open air gallery art show.
I've painted it here, over water in the soft light with the “fernsehturm” in the back as the ubiquitous Berlin navigation marker.
*sources from Wikipedia