Published: Mar 06, 2012 11:47 AM EST

MADISON, Wis. (AP) - Order a sloppy Joe in North or South Dakota, and the waiter may give you a blank stare. The popular beef-on-a-bun sandwich is known to some there as a slushburger. People from parts of the West and Midwest call theirs a Spanish hamburger. And in northwest Iowa? It's a tavern.
 
If ordering lunch now seems unexpectedly complicated, you might want to take a look at the recently completed Dictionary of American Regional English, which explains more than 60,000 regional words and phrases.
 
Known as DARE, the dictionary gives readers a broad history of how the English language is spoken. It traces popular, and not-so-popular, words and phrases to their origins. Then it breaks down how they've been used, with maps showing their geographic range. The final volume of the dictionary, which covers S-Z, is being released this month.
 
It arrives in time for the 2012 presidential election with words like snollygoster, a Southern term for a self-promoting politician.
 
Scholars and word fiends say the dictionary is an invaluable resource. The volumes already in release have been referenced in books and articles about racial and political identity, labor history, human sexuality and even cursing. Curtis Miner, chief curator at The State Museum of Pennsylvania, used the dictionary to help create an interactive map showing speech patterns across the state, including where residents stop saying "soda" and start saying "pop."
 
"DARE is helpful for discerning these cultural fault lines," he said. "It's the only work of its kind that is as comprehensive and exhaustive, because it builds on research that they've been accumulating for decades."
 
Novelists and actors have used the dictionary to create authentic characters, and police have used it to identify suspects. Forensic linguist Roger Shuy cracked open the dictionary in the 1990s to create a pretty accurate profile of Ted Kaczynski from the Unabomber's writings.
 
"It raises awareness of the distinctive communities we have throughout the country. It's easy to look at Americans and say that on the whole, Americans pretty much talk alike, which is true on a very broad level," said Allan Metcalf, executive secretary of the American Dialect Society. "These are the interesting details that make us distinctive."
 
A University of Wisconsin English professor started work on the dictionary about 50 years ago. Frederic Cassidy deployed dozens of field workers, most of them graduate students, around the country to interview people about topics as mundane as the weather and as personal as marriage. They asked more than 1,600 questions and collected 2.3 million responses over six years.
 
But that was just the start. Since then, researchers have vetted the terms to decide what to include. The first volume was finished in 1985. Cassidy died in 2000, with the fourth and fifth volumes unfinished. His tombstone reads, "On to Z!"
 
August Rubrecht was a graduate student studying medieval literature and historical linguistics when Cassidy hired him as a field worker. Now he's a 70-year-old retired English professor.
 
"Everybody thought they could get it done quicker," Rubrecht said. "But it's the nature of dictionary work. It's so meticulous."
 
Researchers thought the fifth volume, which starts with "Slab" and ends with "Zydeco," would be done in 2010. But publication was delayed as funding dried up and new Internet tools increased the amount of work. The release of the final volume is "a huge relief," said chief editor Joan Houston Hall, but the work isn't done.
 
A supplementary sixth volume with an index, maps, and questions and answers from the original field work is in progress. The dictionary team expects to launch an online edition in September 2013, and there's a new website that allows visitors to track some words based on state. A Twitter page offers a DARE word of the day.
 

When Cassidy hired Hall in 1975, "he said, 'Don't expect this to be a full-time job. We'll be done in a few years,'" she recalled. "... Well, it has been a lot more complex than that."
 
With the dictionary finished, Hall has replaced Cassidy's "On to Z!" with a new mantra for the team.
 
"On Beyond Zebra!" she said, with a nod to the Dr. Seuss book by that title. "He would have liked that as well."