Straight as a two-dollar bill.

Got my hands on one of these old beauties while collecting money for a cause last week. You certainly don't see a lot of $2 bills in circulation anymore. 

The United States originally issued two-dollar bills along with the other paper currency after the Legal Tender Act in 1862, and continued to do so until 1966. They always featured Thomas Jefferson, so were sometimes called Toms. The bill never seemed to be as popular as ones, fives, and tens, though, and were thus not printed in as high quantities. In the time the $2 was first printed, it went from being a good deal of money (two days' pay for an unskilled laborer) to a lot less (two hours' pay for unskilled farm work), but neither time nor inflation raised the profile of ol' Tom.  

In 1976 the bill was revived, but the ten-year hiatus had not made it more popular, and it went out of print in 1981. Now they're as seldom seen as the Ike or Susan B. Anthony dollar coins. The Sacagawea coin went out of mint in 2008, so you still see some of them around, but not a lot. I seldom see the newer presidential dollar coins and none of the new "innovation" series, so I think the casinos are hoarding them. 

We just don't like dollar coins in America. I think all coins have an association with cheapness here. The Canadians loved their dollar coin so much they gave it a cute nickname (the Loonie, from the loon on the back). The same goes for their two-dollar coin, which also has a nickname (the Toonie). So even the money in Canada is looney toons. (rim shot)

But coins always got looked down on in the US. I'm not sure when the expression "folding money" (rather than the jingling kind) came into the lingo, as cash worthy of interest, but the oldest reference I know of came from a wartime Fats Waller song, "Cash for Your Trash." The listener is enticed to bring her household trash (old pots and pans and such) to the scrap drive for war use, and receive some money for it, and then canoodle with ol' Fats:

In between we'll do some lovin'

Wide handsome turtle dovin'

Will you listen to me honey

Get plenty of the foldin' money

Yeah, don't settle for that nickel-and-dime stuff; get some actual bills!

As for the two-dollar bill itself, I'd often heard that it was unlucky, but didn't know why. According to Mary Piles, CNB St. Louis Bank Historian (who knew that job existed?), the bad luck tag came from the two being called a deuce, which is also a nickname for the devil. But that's not all! She adds:

One of the reasons the $2 bill was never widely circulated is thought to be due to its negative reputation.

• An urban legend claims that at one time, election rigging was common and the reward for a favorable vote was $2. There was a belief that politicians would purchase votes for $2 therefore, having a $2 bill could be seen as evidence that you had sold your vote. While most likely an urban legend, the myth still gave the bill a sinister reputation.
• In the early 1920s, Prostitution was $2.00 a trick, leading some to refer to the bill as a “whore note.”
• The gambling tracks have a $2.00 window, and if you won, many times you were paid in $2.00 bills. If you were caught with $2’s in your wallet it could lead people to assume you were a gambler.
• The $2 bill was often thought to be bad luck, as “deuce” was a name for the devil. Recipients would tear off one corner, believing it would negate the bad luck of the bill. This caused many of the bills to be taken out of circulation as mutilated currency.

I worked as a teller for a while when I was in school, and I used to buy up $2 bills from other tellers when we cashed out on Friday. That way when I went out drinking with my buddies I would have weird money to draw attention to myself. And I can tell you for a fact that, whether the $2 was lucky or unlucky, I never was. And no, that was not so long ago that (even were I so inclined) I could hire a lady of the evening (ahem) for two bucks. 

There is just one song I know of that mentions a two-dollar bill, by the way (I'd be interested if you know of others). That's Hank Williams's "Hey, Good Lookin'" from 1951. I suspect Hank liked the way it sounded, like money but not a lot of money -- the federal minimum wage in 1951 was 75 cents:

I got a hot rod Ford and a two-dollar bill

And I know a spot right over the hill

There's soda pop and the dancin's free

So if you wanna have fun, come along with me

Less than two years later, Hank was dead, dying on New Year's Day 1953. Was it the mention of the unlucky two that did him in? One has to wonder.