Yes my husband was a US Citizen at the time of the birth of both of our children. They do not acquire citizenship automatically and/or immediately at birth and there is a process (
http://www.uscis.gov/us-citizenship/citizenship-through-parents) that was not completed. Since then I married my husband in the States so should I go through the process described in the above website for my children and if so then what about me.
In all likelihood, your husband was not able to complete the process for his children because he didn't meet the requirements of
section 309 of the Immigration and Nationality Act (acquisition of U.S. citizenship for children born out of wedlock).
One of the following criteria is met before the child reaches 18 years of age:
The child is legitimated under the law of his or her residence or domicile;
The father acknowledges in writing and under oath the paternity of the child; or
The paternity of the child is established by adjudication of a competent court.
Under section 309, one of the above three conditions has to exist before acquiring U.S. citizenship. However, now that your husband has married the children's biological mother prior to their 18th birthday, the first condition (legitimation) has been met. (The Department of State and the USCIS
always considers the subsequent marriage of both biological parents of a child under 18 as an act of legitimation.) Because your husband is a naturalized citizen, he will already have the five years U.S. residence to meet the requirements of section 301. (Five years U.S. residence is a requirement to become a naturalized U.S. citizen.)
He should be able to complete the process now. If the children are in the DR then the best way is to file an
Application for Consular Report of Birth Abroad of a U.S. Citizen.
One other thing. If your husband is not listed on the children's birth certificates, then , in all likelihood, the U.S. Embassy is going to want to see a
court-admissible DNA test. There are plenty of companies that will do one for you though.