If you are having difficulty obtaining money through the more traditional avenues, you can look into getting a loan from the U.S. Small Business Administration (SBA). Please note that the SBA only provides assistance if you are unable to get reasonable, approved financing through traditional channels. Most SBA loans are, in fact, made through banks and other private lenders, which administer and service these loans while not exposing themselves to default risks.
Starting a Business
SBA: Small Business Administration Loans