Abe’s invention, good idea, never used – Lincoln Professional Life One Cent Coin

Today, the Lincoln Professional Life One Cent Coin tells the story of Abraham Lincoln’s submission for a patent 166 years ago.

Having worked on the river, Mr. Lincoln developed his idea for assisting boats over shoals in low water.

On March 10, 1849, he submitted the following patent application:


Be it known that I, Abraham Lincoln, of Springfield, in the County of Sangamon, in the State of Illinois, have invented a new and improved manner of combining adjustable buoyant air chambers with a steamboat or other vessel for the purpose of enabling their draught of water to be readily lessened to enable them to pass over bars, or through shallow water, without discharging their cargoes; and I do hereby declare the following to be a full, clear and exact description thereof, reference being had to the accompanying drawings making a part of this specification. Similar letters indicate like parts in all the figures.

The buoyant chambers A, A, which I employ, are constructed in such a manner that they can be expanded so as to hold a large volume of air when required for use, and can be contracted, into a very small space and safely secured as soon as their services can be dispensed with.

…[detailed description]

What I claim as my invention, and desire to secure by letters patent, is the combination of expansible buoyant chambers placed at the sides of a vessel with the main shaft or shafts by means of the sliding spars, which pass down through the buoyant chambers and are made fast to their bottoms and the series of ropes and pulleys or their equivalents in such a manner that by turning the main shaft or shafts in one direction the buoyant chambers will be forced downwards into the water, and at the same time expanded and filled with air for buoying up the vessel by the displacement of water, and by turning the shafts in an opposite direction the buoyant chambers will be contracted into a small space and secured against injury.

A. Lincoln


In the Hidden Lincoln, his law partner and biographer, William H. Herndon, gave an explanation about Lincoln’s Boat:


As Mr. Lincoln was returning from Congress, with his wife and child, and after passing through some of the States of New England, he entered Canada and was at Niagara Falls. From Niagara he passed westward, going through Detroit. It is quite likely that he took a boat at Detroit for Chicago.

In going to Chicago the boat on which Mr. Lincoln, wife, and child were passengers stranded on some sand bar. The passengers got very tired of their stay on the waters.

The hands of the boat, by order of the commander of the boat, collected all the loose planks, empty barrels, boxes, and the like which could be had.

These planks, barrels, and boxes were used as a kind of buoy; they were shoved by force under the hull of the boat and they, being light and disposed to float by their own small gravity and lifting power, lifted the boat above the surface of the sand bank. The boat rode by the floating power of the things that had been thrust under her.

Mr. Lincoln was very attentive in watching the movements of the hands and the effect of what they did; he occasionally made suggestions that profited the commander. The boat rose gradually higher and higher and finally she was in the deep waters, ready for the onward go.

It was at this time that Mr. Lincoln formed his ideas of his floating vessel, rather the idea of the means to make the stranded boats float.

The idea of Mr. Lincoln was to make a kind of bellows, a great sack that would run around the boat and which could be folded up at pleasure and opened at pleasure, probably by machinery. Wind probably was to be blown into it; swelled out by wind and pushed own with the water and thus it was in idea a means of lifting up the boat.

Mr. Lincoln returned to his old home and he now and here set to work to perfect his patent or to execute his idea and take out a patent on his boat.

Walter Davis, a mechanic, had a shop in Springfield in North Fifth Street, and Lincoln went to that shop, where I have often seen him at work on the model of the boat and Davis’s tools, and made his little model and sent it in to Washington and had it patented.

That model is now in Washington, where it can be seen at any time. This invention was a perfect failure; the apparatus has never been put on any boat so far as known.

W. H. Herndon


Submitted in March, Lincoln received his patent, U.S. Patent 6,469, in May 1849 for “Improved Method for Lifting Vessels over Shoals.”

His model roughly eighteen or twenty inches in length and whittled out of a shingle and a cigar box exists for display at the Smithsonian.

The Lincoln Professional Life One Cent Coin shows against an artistic view of the model boat on display.

Lincoln Professional Life One Cent Coin