Irish couples can come to America and adopt babies and older children.
Americans should be able to adopt Irish babies and children without living there for a year.
If you go back to Ireland I believe they have a grandfather clause. if your grandfather was Irish you can apply for and receive automatic citizenship. If this is your case, then you might be able to bypass the residency requirement.
Citizenship through descent from Irish grandparents
If one of your grandparents is an Irish citizen but none of your parents was born in Ireland, you may become an Irish citizen. You will need to have your birth registered in the Foreign Births Register.
If you are entitled to register, your Irish citizenship is effective from the date of registration.