I am sure that some one here knows of a brand other than Hi Point that is 100% made in the USA, but I don't.
There are 3 brands off the top of my head, Any Springfield item from their 1911 or XD/XDm lineup. Yup they are coming out with a 45acp XDm. Glock, new fan to this brand, not brainwashed yet, lets hope that never happens, and Bersa. Bersa is a great brand that gets little air play here in the US. They manufacture for Military and Police over seas.
Also I understand the allure to the 45acp. But unless you can get a 50 round box of 45 for around 10.00 some place it might be prudent to buy a 9mm pistol instead of 45. You will be able to afford to shoot it more.