Cultural variations
Attitudes and laws regarding adoption vary greatly. Whereas all cultures make arrangements whereby children whose birth parents are unavailable to rear them can be brought up by others, not all cultures have the concept of adoption, that is treating unrelated children as equivalent to biological children of the adoptive parents. Under Islamic Law, for example, adopted children must keep their original surname to be identified with blood relations, and, traditionally, women wear a hijab in the presence of males in their adoptive households. In Egypt, these cultural distinctions have led to making adoption illegal opting instead for a system of foster care. Homecoming Day
In some countries, such as the United States, "Homecoming Day" is the day when an adoptee is officially united with their new adoptive family. See also
References
Barbara Melosh, the American Way of Adoption page 10

Further reading
Argent, Hedi. Related by Adoption: a handbook for grandparents and other relatives (2014)
Askeland, Lori. Children and Youth in Adoption, Orphanages, and Foster Care: A Historical Handbook and Guide (2005) excerpt and text search
Carp, E. Wayne, ed. Adoption in America: Historical Perspectives (2002)
Carp, E. Wayne. Family Matters: Secrecy and Disclosure in the History of Adoption (2000)
Carp, E. Wayne. Jean Paton and the Struggle to Reform American Adoption (University of Michigan Press; 2014) 422 pages; Scholarly biography of an activist (1908–2002) who led the struggle for open adoption records
Conn, Peter. Adoption: A Brief Social and Cultural History (2013) excerpt and text search
Eskin, Michael. The Wisdom of Parenthood: An Essay (New York: Upper West Side Philosophers, Inc. 2013)
Fessler, Ann.
Nevertheless, closed adoption may allow the transmittal of non-identifying information such as medical history and religious and ethnic background. Today, as a result of safe haven laws passed by some U.S. states, secret adoption is seeing renewed influence. In so-called "safe-haven" states, infants can be left anonymously at hospitals, fire departments, or police stations within a few days of birth, a practice criticized by some adoption advocacy organizations as being retrograde and dangerous. How adoptions originate
Adoptions can occur between related or unrelated individuals. Historically, most adoptions occurred within a family. The most recent data from the U.S. indicates that about half of adoptions are currently between related individuals. A common example of this is a "step-parent adoption", where the new partner of a parent legally adopts a child from the parents previous relationship. Intra-family adoption can also occur through surrender, as a result of parental death, or when the child cannot otherwise be cared for and a family member agrees to take over. Adoption is not always a voluntary process. In some countries, for example in the U.K., one of the main origins of children being placed for adoption is that they have been removed from the birth home, often by a government body such as the local authority. There are a number of reasons why children are removed including abuse and neglect, which can have a lasting impact on the adoptee.