Necessity isn't the only mother of invention. Though it wasn't always easy to get patents or the credit they deserved, women are responsible for many items we use today.

1. THE PAPER BAG

iStock

America got a brand new paper bag when cotton mill worker Margaret Knight invented a machine to make them with a flat square bottom in 1868. (Paper bags originally looked more like envelopes.) A man named Charles Annan saw her design and tried to patent the idea first. Knight filed a lawsuit and won the patent fair and square in 1871.

2. KEVLAR

iStock

Lightweight, high-tensile Kevlar—five times stronger than steel—will take a bullet for you. DuPont chemist Stephanie Kwolek accidentally invented it while trying to perfect a lighter fiber for car tires and earned a patent in 1966.

3. THE FOOT-PEDAL TRASH CAN

iStock

Lillian Gilbreth improved existing inventions with small, but ingenious, tweaks. In the early 1900s, she designed the shelves inside refrigerator doors, made the can opener easier to use, and tidied up cleaning with a foot pedal trash can. Gilbreth is most famous for her pioneering work in efficiency management and ergonomics with her husband, Frank. Two of their 12 children, Frank Jr. and Ernestine Gilbreth, humorously wrote about their home/work collaborations in the book Cheaper by the Dozen.

4. MONOPOLY

iStock

Elizabeth Magie created The Landlord's Game to spread the economic theory of Georgism—teaching players about the unfairness of land-grabbing, the disadvantages of renting, and the need for a single land value tax on owners. Fun stuff! Magie patented the board game in 1904 and self-published it in 1906. Nearly 30 years later, a man named Charles Darrow rejiggered the board design and message and sold it to Parker Brothers as Monopoly. The company bought Magie's patent for the original game for $500 and no royalties.

5. WINDSHIELD WIPERS

iStock

Drivers were skeptical when Mary Anderson invented the first manual windshield wipers in 1903. They thought it was safer to drive with rain and snow obscuring the road than to pull a lever to clear it. (Another woman inventor, Charlotte Bridgwood, invented an automatic version with an electric roller in 1917. It didn't take off, either.) But by the time Anderson's patent expired in 1920, windshield wipers were cleaning up. Cadillac was the first to include them in every car model, and other companies soon followed.

6. DISPOSABLE DIAPERS

iStock

Marion Donovan didn't take all the mess out of diaper changing when she patented the waterproof "Boater" in 1951. But she changed parenting—and well, babies—forever. The waterproof diaper cover, originally made with a shower curtain, was first sold at Saks Fifth Avenue. Donovan sold the patent to the Keko Corporation for $1 million and then created an entirely disposable model a few years later. Pampers was born in 1961.

7. THE DISHWASHER

iStock

Patented in 1886, the first dishwasher combined high water pressure, a wheel, a boiler, and a wire rack like the ones still used for dish drying. Inventor Josephine Cochrane never used it herself, but it made life easier for her servants.

8. LIQUID PAPER

iStock

In the days before the delete key, secretary Bette Nesmith Graham secretly used white tempera paint to cover up her typing errors. She spent years perfecting the formula in her kitchen before patenting Liquid Paper in 1958. Gillette bought her company in 1979 for $47.5 million. And that's no typo.

9. ALPHABET BLOCKS

iStock

Children don't read books by anti-suffrage author Adeline D.T. Whitney these days—and that's probably for the better. But the wooden blocks she patented in 1882 still help them learn their ABCs.

10. THE APGAR SCORE

iStock

Life is a series of tests, starting with the Apgar, named after obstetrical anesthesiologist Dr. Virginia Apgar. In 1952, she began testing newborns one minute and five minutes after birth to determine if they needed immediate care. About 10 years later, the medical community made a backronym—an acronym designed to fit an existing word—to remember the criteria scored: Appearance, Pulse, Grimace, Activity, and Respiration.

11. MARINE SIGNAL FLARES

iStock

Communication between ships was once limited to colored flags, lanterns, and screaming things like "Thar she blows!" really loudly. Martha Coston didn't come up with the idea for signal flares all by herself. She found plans in a notebook that belonged to her late husband. The determined widow spent 10 years working with chemists and pyrotechnics experts to make the idea a reality. But she was only named administratrix in the 1859 patent—Mr. Coston got credited as the inventor.

12. THE CIRCULAR SAW

iStock

A weaver named Tabitha Babbitt was the first to suggest that lumber workers use a circular saw instead of the two-man pit saw that only cut when pulled forward. She made a prototype and attached it to her spinning wheel in 1813. Babbitt's Shaker community didn't approve of filing a patent, but they took full advantage of the invention.

13. RETRACTABLE DOG LEASH

iStock

New York City dog owner Mary A. Delaney patented the first retractable leading device in 1908. It attached to the collar, keeping pooches under control, while giving them some freedom to roam. Incidentally, someone named R.C. O'Connor patented the first child harness 11 years later. Coincidence? Maybe.

14. SUBMARINE TELESCOPE AND LAMP

iStock

It's difficult to find any in-depth information about early inventor Sarah Mather. Her combination telescope and lamp for submarines, patented in 1845, speaks for itself.

15. FOLDING CABINET BED

iStock

Sarah E. Goode's folding cabinet bed didn't just maximize space in small homes. In 1885, it made her the first African-American woman with a U.S. patent. The fully functional desk could be used by day and then folded down for a good night's sleep. The Murphy bed came along some 15 years later.

16. THE SOLAR HOUSE

iStock

Biophysicist Maria Telkes's place was in the house—the very first 100 percent solar house. In 1947, the Hungarian scientist invented the thermoelectric power generator to provide heat for Dover House, a wedge-shaped structure she conceived with architect Eleanor Raymond. Telkes used Glauber's salt, the sodium salt of sulfuric acid, to store heat in preparation for sunless days. Dover House survived nearly three Massachusetts winters before the system failed.

17. SCOTCHGARD

iStock

Apparently, it takes a stain to fight one. In 1952, 3M chemist Patsy Sherman was perplexed when some fluorochemical rubber spilled on a lab assistant's shoe and wouldn't come off. Without changing the color of the shoe, the stain repelled water, oil, and other liquids. Sherman and her co-inventor Samuel Smith called it Scotchgard. And the rest is ... preserving your couch.

18. INVISIBLE GLASS

iStock

Katharine Blodgett, General Electric's first female scientist, discovered a way to transfer thin monomolecular coatings to glass and metals in 1935. The result: glass that eliminated glare and distortion, which revolutionized cameras, microscopes, eyeglasses, and more.

19. COMPUTERS

iStock

Women in computer science have a role model in Grace Hopper. She and Howard Aiken designed Harvard's Mark I computer, a five-ton, room-sized machine in 1944. Hopper invented the compiler that translated written language into computer code and coined the terms "bug" and "debugging" when she had to remove moths from the device. In 1959, Hopper was part of the team that developed COBOL, one of the first modern programming languages.