The debt limit (or debt ceiling as it is sometimes called) is a self-imposed cap on the amount of borrowing the United States government can make from other entities (the people, foreign governments, etc). Since the limit is self-imposed, it can also be arbitrarily raised or lowered on the vote of Congress.
EditReagan Speech Relevance
In '
A Time For Choosing', Reagan explains that
We have raised our debt limit three times in the last twelve months.
These increases are as follows:
Aug. 31 1963: raise to $309,000,000,000
Nov. 26, 1963: raise to $315,000,000,000
June 29, 1964: raise to $324,000,000,000
EditSource Links
Statutory Limits on Federal Debt: 1940–Current (whitehouse.gov)