In 1790, with American democracy still a work in progress, American capitalism was taking its own first steps toward maturity.

With his signature, President George Washington approved legislation to create the United States Patent Office, a national system for inventors, makers and tinkerers to own and potentially profit from their ideas. To get approval, simply submit a description of your breakthrough, a small fee, and a working model, not to exceed 12-inches in size.

The Patent Office would drop the model requirement in 1880, but thousands of them survive today, providing a scaled-down glimpse at the challenges and innovations of the era.

"They represent the brilliant minds of Americans in the 1800s and these great ideas they had on a multitude of perceived problems, in everything from toys to furniture to medical to sports to everything," says Debra Hughes, a curator at the Hagley Museum and Library, which sits on the site of the original DuPont factories along the Brandywine River in Wilmington, Delaware.

The Hagley recently received a gift of more than 4,000 patent models from a private collector, Alan Rothschild, adding to its own archive of nearly 1,000 models. They include patents for everything from roller skates to mouse traps, laundry machines to locks and keys. Some models are made of wood, some of different metals and fabrics. They have moving parts, tiny gears, and the occasional dovetail joint. They wouldn't look out of place in a dollhouse.

"Frankly, some of them are pretty stinking cute," says Hughes.

The patent models were big hits a century ago, too. The Patent Office would put them out on display in its Washington D.C. headquarters. By the mid-1800s, more than 100,000 were viewing them annually, strolling through the exhibits on a weekend afternoon.

"You'd see hundreds of washing machine models together...and it was quite the outing."

In sifting through the Hagley's collection, today's visitors can see industry's hopes for the future, but there are also more practical improvements meant to solve the challenges of the day.

"During this time period, most of these would have been aimed for soldiers from the Civil War," says Hughes, pointing to a bronze leg with joints at the ankle and knee. Leather straps would be used to attach it to the thigh.

It is one of many prosthetic devices patented in the 1860s.

"Before the Civil War, and for many years before that, it was basically your carved peg leg...so this was a big improvement."

There were also lots of products geared toward the domestic tasks of women of that era, though there is a notable lack of contributions from women. Just a tiny fraction can be traced to female inventors, though Hughes says that statistic short-changes their role.

"The record is spotty with women invention," she says. "The hardest part about that is that women sometimes invented under an initial and last name because they didn't want it to look like they were a woman."

Major fires in 1836 and 1877 also hampered a complete record of the estimated 200,000 models received by the Patent Office.

By 1880, Congress dropped the model requirement, in part, because it was just becoming a logistical nightmare to store and catalogue them.

"They basically ran out of space," says Alan Rothschild, who along with his wife Ann, authored Inventing a Better Mousetrap, a book tracing patent model history. The Rothschilds donated their collection to the Hagley after closing a patent model museum located outside of Syracuse, New York.

He says the family never intended to amass the country's largest private collection.

"When I found these models, I was fascinated by them. And I bought a few and then I bought a few more, and then I bought a whole lot more," says the retired pharmacist.

To him, the models and what they represent are the heart of the American economy, then and today.

"The patent system is what spawned the Industrial Revolution in this country," he says. "There is no question about it. This is what made the country successful."