Now it happens that some people are interested in the welfare and high development of the human race; but leaving aside those exceptional people, all fathers and mothers are interested in the welfare of their own families. The dearest thing to the parental heart is to have the children marry well and rear a noble family. How short-sighted it is then for such a family to take into its midst a child whose pedigree is absolutely unknown; or, where, if it were partially known, the probabilities are strong that it would show poor and diseased stock, and that if a marriage should take place between that individual and any member of the family the offspring would be degenerates.[39]
Private domestic adoptions: under this arrangement, charities and for-profit organizations act as intermediaries, bringing together prospective adoptive parents and families who want to place a child, all parties being residents of the same country. Alternatively, prospective adoptive parents sometimes avoid intermediaries and connect with women directly, often with a written contract; this is not permitted in some jurisdictions. Private domestic adoption accounts for a significant portion of all adoptions; in the United States, for example, nearly 45% of adoptions are estimated to have been arranged privately.[83]
Common law adoption: this is an adoption which has not been recognized beforehand by the courts, but where a parent, without resorting to any formal legal process, leaves his or her children with a friend or relative for an extended period of time.[88][89] At the end of a designated term of (voluntary) co-habitation, as witnessed by the public, the adoption is then considered binding, in some courts of law, even though not initially sanctioned by the court. The particular terms of a common-law adoption are defined by each legal jurisdiction. For example, the US state of California recognizes common law relationships after co-habitation of 2 years. The practice is called "private fostering" in Britain.[90]
As the idea of institutional care gained acceptance, formal rules appeared about how to place children into families: boys could become apprenticed to an artisan and girls might be married off under the institution's authority.[19] Institutions informally adopted out children as well, a mechanism treated as a way to obtain cheap labor, demonstrated by the fact that when the adopted died, their bodies were returned by the family to the institution for burial.[20]

Foster care adoption: this is a type of domestic adoption where a child is initially placed in public care. Many times the foster parents take on the adoption when the children become legally free. Its importance as an avenue for adoption varies by country. Of the 127,500 adoptions in the U.S. in 2000[83] about 51,000 or 40% were through the foster care system.[84]
These practices have become significant social and political issues in recent years, and in many cases the policies have changed.[176][177] The United States, for example, now has the 1978 Indian Child Welfare Act, which allows the tribe and family of a Native American child to be involved in adoption decisions, with preference being given to adoption within the child's tribe.[178]
Open records: Movements to unseal adoption records for adopted citizens proliferated along with increased acceptance of illegitimacy. In the United States, Jean Paton founded Orphan Voyage in 1954, and Florence Fisher founded the Adoptees' Liberty Movement Association (ALMA) in 1971, calling sealed records "an affront to human dignity.".[158] While in 1975, Emma May Vilardi created the first mutual-consent registry, the International Soundex Reunion Registry (ISRR), allowing those separated by adoption to locate one another.[159] and Lee Campbell and other birthmothers established CUB (Concerned United Birthparents). Similar ideas were taking hold globally with grass-roots organizations like Parent Finders in Canada and Jigsaw in Australia. In 1975, England and Wales opened records on moral grounds.[160]
Some adoptees reject the idea of reunion. It is unclear, though, what differentiates adoptees who search from those who do not. One paper summarizes the research, stating, "...attempts to draw distinctions between the searcher and non-searcher are no more conclusive or generalizable than attempts to substantiate...differences between adoptees and nonadoptees."[169]
Unlike guardianship or other systems designed for the care of the young, adoption is intended to effect a permanent change in status and as such requires societal recognition, either through legal or religious sanction. Historically, some societies have enacted specific laws governing adoption; where others have tried to achieve adoption through less formal means, notably via contracts that specified inheritance rights and parental responsibilities without an accompanying transfer of filiation. Modern systems of adoption, arising in the 20th century, tend to be governed by comprehensive statutes and regulations.