As you're probably already aware, pretzels are a type of baked snack food made from dough.  They come in both hard and soft varieties, as well as salty and sweet flavors. 

Most pretzels have a signature shape that resembles a knot.  The pretzel's unique shape is a symmetrical loop created by intertwining the ends of a long strip of dough and then folding them back on each other, forming a “pretzel loop." 

Legend has it that the pretzel was invented by an Italian monk in the year 610 A.D. To reward young children for learning their prayers, he supposedly folded strips of bread dough to resemble the crossed arms of praying children.  He called his creation pretiola, which meant “little rewards." 

Whether this legend is the true origin of the pretzel, no one knows for sure.  Most experts agree, though, that the pretzel does have Christian origins. 

For example, in the Catholic Church, pretzels held religious significance because of their ingredients.  When made with a simple recipe of only flour and water, they could be eaten during Lent, when Christians were forbidden to eat certain foods. 

Over time, pretzels became associated with both Lent and Easter.  In fact, pretzels were often hunted on Easter morning just like many children hunt eggs today. 

German and Swiss immigrants introduced the pretzel to North America in the 19th century.  In 1858, Casper Gloor, a Swiss baker and member of the Swiss Colonization Society, settled in Tell City, Indiana. 

He soon became famous for his pretzels, which he baked from a secret Swiss recipe.  Today, the recipe remains a secret, and Tell City Pretzels still attract pretzel lovers from all over the world. 

It wasn't until pretzels were introduced to America that hard pretzels came into existence.  In 1850, the first commercial hard pretzel bakery opened in Lititz, Pennsylvania.  Hard pretzels became popular as a snack food since they were more durable than soft pretzels when kept in an airtight container. 

In the 20th century, pretzels became very popular in large cities.  In particular, the large Italian-American population of Philadelphia made pretzels an integral part of its local cuisine.  Today, the average Philadelphia resident eats approximately 12 times more pretzels than the average American. 

Pennsylvania remains the center of pretzel production in the United States today, making 80 percent of the nation's supply.  The U.S. pretzel industry is worth more than $550 million annually, and the average American eats more than 1.5 pounds of pretzels each year. 

Today, pretzel connoisseurs can enjoy their favorite snack with a wild variety of seasonings, including special glazes, salt crystals, cinnamon, sugar, and various nuts and seeds.  Pretzels can also be found in many different shapes, such as sticks, rods, loops, braids, and even letters.