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Curious Iowa: What have Iowans invented?
A look into the history of three inventions made by Iowans
Mar. 17, 2025 5:30 am, Updated: Mar. 17, 2025 8:32 am
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Our lives have been made easier, more full and more fun by inventions. But which of those inventions — some we use every day — were thought up by Iowans?
A Cedar Rapids resident wrote to Curious Iowa with that question. The series from The Gazette answers questions about our state, its people and our culture. This week, we looked into the history of the bread-slicing machine, trampoline and computer.
Commercial bread-slicing machine
Sliced bread kept fresh in a bag has saved Americans time since 1927. We have Iowa native and Davenport resident Otto Frederick Rohwedder to thank for that.
“He had this idea about 1912 and spent a lot of time working on a design, working on plans, figuring it out, calibrating the slicers, all of this design stuff,” Paula Johnson, food history curator at the National Museum of American History, told The Gazette.
At the time he worked as a jeweler in St. Joseph, Missouri, but in 1916 he returned to Davenport. A year later he faced a significant setback when there was a fire in the Illinois factory that was producing the machine, destroying Rohwedder’s designs.
“So, he picked himself up and decided to keep going, redraw the designs,” Johnson said. It would take 10 years for Rohwedder to complete the commercial bread slicing machine.
The machine was first used in 1928 by the Chillicothe Baking Company in Chillicothe, Missouri. That year Rohwedder applied for a patent for the slicer.
St. Louis baker Gustav Papendick struck gold when he combined the collapsible bread tray with Rohwedder’s machine, allowing loaves to be wrapped and kept fresh.
The Oct. 28, 1929 edition of the Quad-City Times included this description, “The machine slices a loaf of bread at a time, at the rate of six loaves to the minute.”
Davenport’s H. Korn Baking company became the fourth bakery in the world to slice bread. A Dec. 23, 1928 Quad-City Times article described how the machine worked:
“Shortly after the loaves leave the oven and prior to the time when they are properly cooled and sent thru the wrapping machine, they are sliced by the Rohwedder bread slicer. This machine gently but rapidly pushes the loaves thru a series of alternating blades which slice the entire loaf simultaneously. There is no crumbing and no crushing of the loaf and the result is such that the housewife can well experience a thrill of pleasure when she first sees a loaf of this bread with each slice the exact counterpart of its fellows. So neat and precise are the slices and so definitely better than anyone could possibly slice by hand with a bread knife, that one realizes instantly that here is a refinement that will receive a hearty and permanent welcome.”
On Feb. 28, 1929 Tom J. Korn wrote to Rohwedder, describing how he initially was skeptical of the invention but had a change of heart.
“The best part of sliced bread as I see it is that competition is absolutely at a loss to combat it. This was proven in our territory and it’s the (first) time that our competitors came to us and admitted we had them licked.”
Trampoline
The trampoline was invented by gymnast George Nissen of Cedar Rapids. Sixteen-year-old Nissen was inspired to create the trampoline after watching aerialists fall into safety nets and bounce up again at a circus show.
An interview with Nissen in the Nov. 7, 1999 edition of The Gazette recalled Nissen and friends using scrap parts “to stretch canvas onto a crude frame with springs made with rubber strips from inner tube tires.” Those “scrap parts” included the frame of Nissen’s bed.
Nissen brought his invention to his summer job as a YMCA camp counselor.
“The kids had so much fun jumping on it,” he said. “They’d rather do that than go swimming.”
Nissen went on to study at the University of Iowa where he became a three-time NCAA gymnastics champion and an All-American diver. He graduated in 1937 with a degree in business administration.
Along with two college friends, Nissen formed “The Three Leonardos,” a traveling performance group that put on acrobatic and diving shows in Mexico and the U.S. During his tenure with the Leonardos, Nissen tinkered away at the trampoline — a name inspired by the Spanish word for diving board, el trampolín.
In the first year after Nissen perfected his invention he sold about 10 trampolines. He brought it with him as he toured and performed tumbling shows at high schools.
“There was no market for it because nobody has ever seen one,” Nissen told The Gazette. “I had to demonstrate its worth. And that was always my forte. I like to make new things and then market them.”
During World War II, Nissen joined the Navy. He practiced back somersaults on the deck of a destroyer, which was no easy feat.
“You were never sure where the deck was going to be when you landed,” he told Gazette Olympics correspondent Tom Ecker in 2000.
In 1946, he incorporated the Nissen Trampoline company in Cedar Rapids, which would become the world’s largest gymnastics equipment manufacturer.
In 1962, the International Gymnastics Federation recognized trampolining as an official sport. After decades of lobbying and introducing the sport around the globe, trampolining made its Olympic Games debut in the 2000 Sydney games. Nissen, who was 86 at the time, attended The Games and was invited to jump on the Olympic trampoline.
Computer
While a rushed online search might lead you to believe the Electronic Numerical Integrator and Computer (ENIAC) was the world’s first computer, the true first computer was built at Iowa State in the basement of the Physics Building.
In 1937, physics and math professor John Vincent Atanasoff began making plans to improve existing calculating machines by making them faster and more accurate. In March of 1939, he made a formal application to Iowa State College for funding, materials and a graduate assistant. The college approved a grant for $650 and Atanasoff hired physics graduate student Clifford Berry.
Between 1939 and 1942, Atanasoff and Berry built the Atanasoff-Berry Computer (ABC). This invention marked the first time a computer stored information on its main memory.
So, how did the ENIAC, built between 1943 and 1945, steal the show? The answer lies with a missed patent opportunity on Iowa State College’s part and a scientist named John Mauchly.
Atanasoff met Mauchly in December 1940 at an annual meeting of the American Association for the Advancement of Science. Mauchly was interested in Atanasoff’s computer, but Atanasoff told him he couldn’t share information that would jeopardize the patent. Although, Atanasoff invited Mauchly to see the computer in Ames because he didn’t believe Mauchly would take advantage of him.
In June 1941, Mauchly visited Ames and spent four days with Atanasoff, Berry and the ABC, discussing its design and even taking notes from a 35-page explainer on how the computer worked. During this time, it was not uncommon for Atanasoff to meet with other influential scientists who were interested in or working on computing projects.
According to Iowa State University, Atanasoff assumed that the patent process would be completed by Iowa State College. The attack on Pearl Harbor in 1941 interrupted these plans and moved Atanasoff’s and Berry’s careers in new directions.
Berry moved to California for a position in national defense and Atanasoff became a civilian consultant to the Naval Ordnance Laboratory in Washington, D.C.
The patent paperwork was left to Iowa State College and its patent attorney Richard Trexler. The college never applied for the patent.
In 1964, J. Presper Eckert and Mauchly patented the ENIAC. Three years later, Honeywell Inc. filed a patent lawsuit against Sperry-Rand Corp., which owned the ENIAC patent.
In 1973, Honeywell v. Sperry-Rand Corp. concluded with U.S. District judge Earl Larson ruling that, “Eckert and Mauchly did not themselves first invent the automatic electronic digital computer, but instead derived the subject matter from one Dr. John Vincent Atanasoff.”
Judge Larson overturned the ENIAC patents and lauded the ABC as the world’s first electronic digital computer. Larson also ruled that the concept of the computer was unpatentable
Unfortunately, the publication of the ruling was overshadowed by the Saturday Night Massacre, a turning point in the Watergate scandal.
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Comments: bailey.cichon@thegazette.com
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