Does the fact that your child is adopted influence immigration?

Question

If you would marry a woman with a child from a previous relationship and you adopt this child and become the legal guardian for this child. If apply for this This visa would the fact that the child of yours is not a blood relative matter? Assume for the purposes of this discussion that the child is under 21 and single.

Answer 1

First, note that a stepchild counts as a "child" for US immigration (though not citizenship) purposes, if the stepparent and the child's biological parent married before the stepchild turned 18. So in the case you described, where the child is your stepchild, there is no need for you to adopt the stepchild in order for the stepchild to be able to immigrate as a derivative beneficiary or in a category for the child of the petitioner. See 8 USC 1101(b)(1)(B):

(b) As used in subchapters I and II-

(1) The term "child" means an unmarried person under twenty-one years of age who is-

(B) a stepchild, whether or not born out of wedlock, provided the child had not reached the age of eighteen years at the time the marriage creating the status of stepchild occurred;

For an adopted child to count as a "child" for US immigration and citizenship purposes, they would (unless adopted as an "orphan" or under the Hague convention process) generally need to have been adopted before the child turned 16, and the child must have resided with and have been in the legal custody of the adopting parent for 2 years. See 8 USC 1101(b)(1)(E)(i):

(E)(i) a child adopted while under the age of sixteen years if the child has been in the legal custody of, and has resided with, the adopting parent or parents for at least two years or if the child has been battered or subject to extreme cruelty by the adopting parent or by a family member of the adopting parent residing in the same household: Provided, That no natural parent of any such adopted child shall thereafter, by virtue of such parentage, be accorded any right, privilege, or status under this chapter; or

Answer 2

For US immigration purposes, an adopted child is a child. Note for example that at Green Card for Employment-Based Immigrants acceptable evidence includes "adoption decree."

The controlling law is 8 USC 1101(b)(1). Since it's not clear from the question whether the child is under the intending immigrant's guardianship or truly "adopted" I include the paragraph that covers stepchildren:

(B) a stepchild ... provided the child had not reached the age of eighteen years at the time the marriage creating the status of stepchild occurred;

...

(E) (i) a child adopted while under the age of sixteen years if the child has been in the legal custody of, and has resided with, the adopting parent or parents for at least two years ...