Did you have cereal for breakfast today? If so, you have lots of company: 98 percent of American kids eat cereal, which makes it a hot item at the grocery store.

More than 2 billion packages of cereal were sold in the United States last year. That’s more than seven boxes’ worth for every man, woman and child. Since adults eat less cereal than kids do, you probably ate more than your share!

Walk down any supermarket cereal aisle and you’ll see a dizzying array of choices. Some, such as Post Grape Nuts, have been around for more than a century; others are younger than you are.

A recent push is for more whole grains and less sugar, a trend that takes cereal back to its roots in an 1860s health movement nurtured by C.W. Post and two brothers, J.H. and W.K. Kellogg — names still seen on cereal boxes. These men knew that fiber-filled grains were better for people than the heavy, meat-rich breakfasts then popular. But creating a tasty alternative wasn’t easy: The first breakfast cereal, Granula, which came out in 1863, was so tough the bran had to be soaked overnight to avoid breaking some teeth.

The Kelloggs, Post and others spent years working on ways to flatten, puff and shred their wheat, oats, corn and rice. And the public was hungry for what they made. By 1902, 30 cereal companies were competing in Battle Creek, Mich., which became the hub of the cereal world. From this came products we still buy today: Kellogg’s Toasted Corn Flakes was introduced in 1906, and General Mills brought out Wheaties in 1924 and Cheerioats (later called Cheerios) in 1941.

Not every new cereal was a hit, though. An especially unappetizing attempt was Tryabita, a short-lived 1903 cereal that tasted like celery!

To attract customers, cereal makers invented characters to sell their products. Rice Krispies brought in Snap! in 1933, with Crackle! and Pop! to follow. Tony the Tiger was born in 1952 and Cap’n Crunch sailed into grocery stores in 1963.

Advertisers found that radio and, later, TV were good places to sell cereal, and characters such as Mickey Mouse and Superman became popular pitchmen. Long before becoming president, Ronald Reagan touted Wheaties on the radio.

Cereal for kids, much of it loaded with sugar, took off in the 1950s. Inexpensive prizes — including decoder rings, trading cards, paper planes and comic books — kept little consumers wanting more. The prize frenzy peaked in the late 1980s when some cereal makers put money — as much as $500 — in their boxes.

Robb Berry is a cereal expert, having collected more than 3,000 boxes, some with cereal still inside. His favorite prize: four glow-in-the-dark monster posters from Super Sugar Crisp in 1975. His favorite character: Quisp, a “really brainy little alien guy.”

Berry, who lives in Minnesota, started collecting “as a lark” 25 years ago when he was a teen. “I have the only known unopened Freakies box, from 1974,” he boasts. It had fallen behind a shelf in a grocery in Eagle, Wis., where it sat unnoticed for years. Berry paid $770.67 for it.

Occasionally he’ll break open a vintage box and sample its pleasures. “I once ate a two-year-old box of Kaboom,” he said, adding: “I now know what it’s like to eat Play-Doh.”