One thing that is very difficult to grasp by the modern mind is that even Americans expected and wanted their troops to be clothed to fight in their “dress uniforms.”
This is why Washington’s suggestion to use Riflemen’s shirts and leggings/breeches/overalls for the entire Army was never approved, though it became the “normal” fatigue or “work” uniform when doing strenuous or hard/dirty/sweaty labor.
Washington remembered when he commanded the Provincial Virginia Regiment after the Seven Years War, even though the men OFFERED to have the costs of a real uniform subtracted from their pay, it took a few years to fully clothe them in GOOD uniforms. “Riflemen’s Dress” was one way to quickly and as inexpensively as possible clothe the new American Army in “Uniform Uniforms” that were practical. He and others did note the possible psychological advantage it may have posed (at least for a while) on the minds of the British to think they were opposing “The Feared Riflemen.” However, the poor showing of Riflemen early in the war, until Saratoga, dispelled that myth.
There was some good thinking about having Soldiers wear real “Uniform Uniforms” in the time period when Commanding Officers had to rely often on their eyesight to distinguish friendly vs enemy troops on a battlefield and especially if one did not have Cavalry or Horse Troops assigned to relay messages (or if there were not enough of them). There was one American Regiment at the start of the ARW that showed up in Red Uniforms and Washington had to compromise by ordering an overcoat to cover the color in battle. Not sure how that worked out in the real world, though. This was shown to be morbidly important during the Un-Civil War where at the Battle of 1st Manassas, BOTH Union and Confederate forces showed up in Blue and Cadet Grey and both sides fired on their own troops in the confusion of battle.
We also have to remember that no matter how realistic the person may have wanted a portrait painted, they usually GOT a fair amount of romanticism from period Artists. The Artists knew if they painted things in a too lifelike manner, they may or would not have been paid. Further, if one was to go to the expense of having a portrait painted, one usually “wore their best clothes” and then Artists took some Artistic license when painting them.
Finally, portraits or at least good drawings of “common people” or “tradesmen” were much more available in Britain and France than America. There were enough Artists and enough of a market for the work in Europe, but not yet in America in the 18th century. So we have to look for period British and French drawings today, to see what types of clothing that different classes of people wore then. We also can’t forget that clothes came to America or American’s were still ordering clothes from Europe until and even after the ARW. As late as 1768, Washington had at least one British Tailor where he ordered his best clothing.
Gus