The United States of America was almost the last civilized country to establish such a system, which was authorized by act of Congress in 1910, and went into operation in a few designated cities in January, 1911.

The number of offices at which it was in operation was rapidly increased, and the number in 1914 was about 10,000.
Any one ten years of age may become a depositor.

Deposit must be made always in multiples of one dollar.

Not more than $100 will be accepted for deposit in any one calendar month, and nothing after the total balance to the depositor's credit is as much as $1000, exclusive of accumulated interest.

However, amounts less than one dollar may be saved for deposit by purchasing a ten-cent postal savings card and affixing ten-cent postal savings stamps until the nine blank spaces are filled.