Final answer:
The two dominant denominations found in the US are Catholicism and Protestantism.
Step-by-step explanation:
The two dominant denominations found in the US are Catholicism and Protestantism. Catholicism is the largest religious body in 40 percent of US counties, especially in the Northeast, West, and Southwest, which can be attributed to 19th and early 20th-century immigration from Roman Catholic countries in Europe. Protestantism includes a variety of denominations such as Baptist, Episcopal, Lutheran, Methodist, and Pentecostal, with the Baptist denomination being particularly dominant in the Southeast, known as the Bible Belt.