Sometimes, the child you're meant to adopt and raise lives in another state. Maybe the birth mother was contacted by an attorney or the child is in a foster system across state lines. While interstate adoption is completely legal, clashing state laws can make things messy and there are a lot of legal regulations required of an interstate adoption.
When New Jersey became the last state to accept the Interstate Compact on the Placement of Children (ICPC) in 1990, all states had a piece of legislation that set guidelines for the placement of children being adopted out-of-state. The way the compact works is as such: every state has an office that monitors the sending and receiving of an adoptee between strangers. The sending office is identified by the state from which the child is moving from. The receiving office is where the child is moving to, assumed to be the state of residence of the adoptee's adoptive parents. The sending office is the one that reserves the right to check-in with the adoptive arrangement and can also remove a child from an adoptive home if the placement is not working in the child's best interest. The removal of children from adoptive homes is unlikely due to criminal background checks are required of most home studies.
Note: A child can be moved between a birth mother and birth grandmother without the state needing to be involved.