US was industrializing throughout the 1800's, there are empty/converted factories all up and down the East Coast from these. In New England, it was a lot of textiles, metalworking, shoes, parts, etc. What tariffs protected that growth? To me it seems to be a rising production due to rising demand for those products, as factories/mass production wasn't common prior to 1800.

The US had protective tariffs and regulations (along with a lack of free trade agreements) which definitely protected foreign goods and companies from entering the country. Protective tariffs literally started with George Washington with the goal of "the encouragement and protection of manufactures".