By 1980, General Mills had accumulated so much brand memorabilia that the company established an archive at its headquarters, in Golden Valley, Minn. The archive grew with the 2001 purchase of Pillsbury, a Minneapolis milling rival with its own rich marketing history. Several years ago, General Mills moved the archive to a former Pillsbury building in Minneapolis near the Mississippi River, not far from the site of its first flour mill.

The archive, which is closed to the public, houses thousands of artifacts in about 3,000 square feet of temperature- and humidity-controlled space. In honor of the company’s 150th anniversary, General Mills made selected items from the archive available to members of the news media.

Among the photos, packaging and promotional items are an early rendering of the character Betty Crocker, who was created in 1921 to answer consumers’ baking questions; cookbooks from the 1880s, when General Mills was known as the Washburn Crosby Company; some of the first clay animation models of Poppin’ Fresh, the Pillsbury Doughboy; and a box of Cheerioats, the original name of Cheerios. The name was changed in 1945 to settle a trademark lawsuit.

“I’ve been here 20 months,” said the corporate archivist, Jessica Faucher. “It’s hard to memorize 150 years of history.”

Ms. Faucher said consumers and longtime employees had contributed some items to the collection and archivists had discovered others on eBay. Three shelves contain two copies of virtually every printing of the Betty Crocker cookbook since 1950. The book is known as “big red” for the original’s color and thickness.