The Congress finds that Federal savings and loan associations and national banks should have the authority to assist in financing the organization and operation of any State housing corporation established under the laws of the State in which the corporation will carry on its operation. It is the purpose of this section to provide a means whereby private financial institutions can assist in providing housing, particularly for families of low- or moderate-income, by purchasing stock of and investing in loans to any such State housing corporation situated in the particular State in which the Federal savings and loan association or national bank involved is located