Because there was not enough money for the surface, the first motorcycle race, on the 29Short after the opening of the new track the Second World War broke out and motor racing stopped.
During the war the surface was badly damaged because allied forces drove with their tanks on the circuit.
Ironically, the circuit came in financial trouble because of the expensive reconstruction in 2002!
One moment it looked even that Formula One would never return to Hockenheim because the costs where higher than the profits.
This race was won by Jochen Rindt who died after a crash at Monza later that year and became The next year Formula One returned to the Nürburgring.
But after the grave accident from Nikki Lauda in 1976, the Nürburgring was found too dangerous and the German Grand Prix came back to Hockenheim.
This page describes the history of this particular race track, in the South West of Germany, from the first "Dreieckskurs" to the current "Hockenheimring Baden-Württenberg".
Despite to what many sources claim, Hockenheim is not built as a test track for Mercedes.
It also was a circuit that gave, just like Monza, some variation to the Formula One calendar.
From 1977 to 2006 the German Grand Prix was held at Hockenheim, except in 1985 when there was no German Grand Prix.
Until 1994 they where originally named Bremskurve 1, 2 and 3 (Chicane 1, 2 and 3).
A solution came when Hockenheim made a deal with the Nürburgring to alternate the German Grand Prix between both circuits.
Now you can ask if that reconstruction was necessary for a race which is only held every two years!