Money in the United States today just isn't what it used to be.

It's all about change.

From pence and pounds to the "small-size" currency used today, the Federal Reserve Bank of San Francisco is presenting the development of American money since the American Revolution in an online exhibit.

The exhibit is designed to make sense of how alterations in currency reflect American history.

On display are images of one-third dollars, bank notes, 50-cent shinplasters, treasury coin notes -- all legal tender of the past. Accompanying the exhibit pictures are notes on the historical context of the displayed currency.

For instance, if you want to better understand the use of national gold bank notes in California during the gold rush, the exhibit's historical overview of metal standards might just fit the bill.

You can navigate through the exhibit in a variety of ways, from viewing the currency of individual eras such as the Civil War or the Industrial Revolution to reviewing the imagery and art of the bills with their portraits and state seals.

The online exhibit is a companion piece to the American Currency Exhibit on display in the lobby of the Federal Reserve Bank in downtown San Francisco.