The main purpose of this legislation, known as the UNLOCK Housing Act, is to make it easier to use federal lands for building affordable housing. The act aims to address the growing need for affordable housing, particularly for low-income families, by designating the development of such housing as a public purpose. One of the key provisions of the act is the amendment to the Recreation and Public Purposes Act, which now explicitly states that creating and maintaining affordable housing for low-income families is considered a public purpose.