The U.S. dollar bill celebrates its 150th birthday today.  But as the Financial Times reports, this isn't the cheeriest birthday that the green back has seen:

The US dollar, which turned 150 this week, is finally starting to act its age. After a stormy childhood, it spent much of its 20th century prime as the unquestioned linchpin of global finance, particularly during the Bretton Woods era, when it was tied to gold. Today, the greenback is the primary reserve currency, largely due to tradition and lack of alternatives. With traders unwilling to bet on the troubled euro and unable to bet against the renminbi, gold’s nominal record in dollar terms this week shows unease about the dollar’s long-term strength.

Click here to read more about the tumultous history of America's experiment with paper currency.