Have you ever adopted a baby ,?
No i am not a fan of you assuming the  the parenting of another person's biological  child
So adaption dates back to what era?
I think Modern systems of adoption arose in the  20th century and tends to be governed by comprehensive statutes and regulations.
Any international laws on adoption?
International adoption
International adoption (also referred to as intercountry adoption or transnational adoption) is a type of adoption in which an individual or couple becomes the legal and permanent parent(s) of a child who is a national of a different country. In general, prospective adoptive parents must meet the legal adoption requirements of their country of residence and those of the country whose nationality the child holds.
International adoption is not the same thing as transcultural or interracial adoption. However, the fact is that a family will often become a
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.
History.
History Antiquity.
- Adoption for the well-born
While the modern form of adoption emerged in the United States, forms of the practice appeared throughout history.