People sold off bank stocks, making them worthless.
Explanation:
The Stock Market Crash of 1929 caused a series of bank runs which destroyed the people's trust in the banking system. It began as a rumor that the banks were unable to pay cash which then transcended to panic among customers causing them to withdraw their funds en masse. They also spent little thus causing a stagnant economy. People withdrew their cash from the banks thus causing the solvency of many banks.
Banks in turn liquidated their loans and sold their assets at very low costs.
The invention from Song, China that had the greatest influence on the spread of learning was paper and printing. This helped to get the public interested in reading.
During the 2008 presidential campaign, the two leading candidates for the Democratic nomination were "an African American man and a former first lady" The former being Obama and the latter being Clinton.