Although open adoptions are thought to be a relatively new phenomenon, most adoptions in the United States until the twentieth century were open. Until the 1930s, most adoptive parents and biological parents had contact at least during the adoption process. In many cases, adoption was seen as a social support: young children were adopted out not only to help their parents (by reducing the number of children they had to support) but also to help another family by providing an apprentice.
All states allow an adoptive parents access to non-identifying information of an adoptee who is still a minor. Nearly all states allow the adoptee, upon reaching adulthood, access to non-identifying information about their relatives. Approximately 27 states allow biological parents access to non-identifying information. In addition many states give such access to adult siblings. Identifying information is any data that may lead to the positive identification of an adoptee, biological parents, or other relatives. Nearly all states permit the release of identifying information when the person whose information is sought has consented to the release. Many states ask biological parents to specify at the time of consent or surrender whether they are willing to have their identity disclosed to the adoptee when he or she is age 18 or 21.5. If consent is not on file, the information may not be released without a court order documenting good cause to release the information. A person seeking a court order must be able to demonstrate by clear and convincing evidence that there is a compelling reason for disclosure that outweighs maintaining the confidentiality of a party to an adoption.[24] In Alabama, Alaska, Delaware, Kansas, New Hampshire, and Oregon, there is no requirement to document good cause in order to access their birth certificates.[25][26][27][28] Some groups, such as Bastard Nation, One Voice,[29] and Origins USA,[30] campaign for adoptees' automatic access to birth certificates in other US states.

There are sometimes problems concerning birth mothers and adoption agencies who neglect to make sure the proper paperwork is done on the birth father's part. It is crucial to remember that no child can be relinquished legally without the birth father's consent, except in Utah. He must be given the chance to claim custody of the child. For this purpose, many states have established a Putative father registry, although some adoption activists see these as a hindrance rather than a help.[22]

A 1996 study reported in Child Development found that all the children studied “reported positive levels of self-esteem, curiosity about their birthparents, and satisfaction with the openness situation” regardless of whether their adoptions were closed, semi-open, or open. What this seems to mean is that the child's sense of security in his adoptive family is more important than contact with the birth family.

There are also private search companies and investigators who charge fees to do a search for or assist adoptees and birth mothers and fathers locate each other, as well as to help other types of people searching. These services typically cost much more, but like search organizations and search angels, have far greater flexibility in regards to releasing information, and typically provide their own intermediary services. However, they may not circumvent the law regarding the confidentiality process.