Domestic Eligibility Requirements?

Hello. I am quite new to these forums. My husband and I are looking into adoption after two m/c, one last year, and one very recent, we recently lost our twin girls to twin to twin transfusion syndrome. I myself am adopted from Korea (went thru Spence Chapin) but i dont know much about domestic adoptions. I know a lot of international adoptions, each country has their own set of requirements and guidelines (ie length of marriage, physical and mental health, weight) i was wondering what kind of requirements there are to adopt domestically? I would appreciate any information you can provide. Thanks