There were enough surviving soldiers with upper limb amputations to inspire the creation of specialized cutlery for one-handed use. This article discusses the issuance by the U.S Government to one-handed veterans of the Detmold knife, a knife/fork combination tool invented by an Army surgeon from New York.

https://academic.oup.com/milmed/article/181/4/395/4158518

Possession and use of folding pocket knives was near-universal in the era, but traditional designs were difficult or impossible for one handed individuals to open. This led to the creation of the “one arm Barlow” type folding pocket knife. These had a notch cut into the blade tip which was hooked on the edge of a pocket to open, which could easily be done with one hand. Re-creations of this style are still available today

https://www.bladehq.com/item--Bear-and-Son-One-Arm-Bandit-Barlow--39176

While mandatory access for the disabled is pretty a recent concept, the Pension Office is a notable early attempt. The massive Union Army of the Civil War resulted in a massive number of veterans, some of them disabled, who qualified for pensions- and, their widows and sometimes their children as well. Processing those claims required a lot of staff, and an office had to be built to house that staff. The job of designing that building was given to Brig. General Montgomery Meigs, in 1881.

Meigs is mostly famous now for his decision to set a Union soldiers' cemetery on the estate of Robert E Lee in Arlington , but he was a very innovative and capable architect. He assumed that the Pension Office would have disabled veterans on the staff. Elevators were as yet novelties, so he designed the stairs of the building to have low risers , and deep slightly-tilted treads, that made them easier for the disabled to manage. Mindful of the miserable summers in Washington DC, he also went to great lengths to ventilate the building, creating a large open courtyard, with a clerestory that would allow hot air to rise up to and out of the roof. That also created a draft through the staff offices, which had ingenious gaps in the brickwork under the windows to allow in air.

Unfortunately, Meigs' ingenuity was not appreciated. Most people thought the place was just a big Italianate brick barn, and so it did not spawn a host of equally-accessible imitations. But Meigs' himself was never bothered by criticism: like a number of famous architects, he seemed to have had very few doubts about his projects generally, and this was his last. In time it became home to other bureaus: the General Accounting Office was the last tenant and just filled up the bottom of the great hall with offices. When the GAO moved, the place became empty, was almost torn down. Eventually , however, it was recognized as being as innovative as it was, and is now the National Building Museum: where ( when it's open) among many other things you can learn more about the history of disabled access in architecture.

http://www.streetsofwashington.com/2014/01/the-pension-building-montgomery-meigs.html