The reason people want "made in USA" is twofold:
Primarily, they expect a better and more consistent quality level for USA made.
Second, they believe in supporting USA jobs/business.
So, the question is, what kind of tool can you produce for a competitive price that has quality that is above and beyond the Taiwan and China stuff you see available? An associated question would be, what tools do the members here see that the Taiwan and China made stuff is not of good enough quality?
If you can consistently produce and market a high quality version of those tools, at a somewhat competitive (not lowest) price, you will have a market. Keep in mind that you have several very sophisticated competitors. Those include Snap-on (and Williams), Wright, SK, Cornwell, Proto (Stanley/Black & Decker). You'll have to substantially underprice them to get a toehold in the market. Or, come up with a unique and useful and high quality tools that they don't currently produce. If you can do that, you should directly market yourself to Snap-on or Stanley Black and Decker as an employee. They should pay you well if you have those capabilities.
Most tool production requires large scale forging capabilities. So, you might be best served to do precision tool manufacturing, focusing on tools that can be made in a machine shop with CNC tooling, out of manufactured materials rather than raw materials. That would lower the start-up costs and scale of the business by a huge step.
Most small production shops focus on a niche product, generally invented and produced by an enthusiast with a specialty in something specific of interest to them.
I make and sell a small product, for a very niche market. My costs are low, my skill level is high in that one item, and I make and sell a few hundred a year. It does not, and will never, substantially increase my annual income. The good side of it is that nobody will ever compete with me on it; the learning curve to produce the item is such and the market is so small that no-one will invest either in the skill to compete at my price, or the machinery needed to automate the production and lower the cost.