Final answer:
The New York State courts allowed unmarried couples to adopt children based on the principle of equal protection under the 14th Amendment, ensuring that same-sex and opposite-sex couples receive the same treatment under the law.
Step-by-step explanation:
The New York State courts ruled that a couple does not have to be married to adopt a child, primarily based on the principle of equal protection. The ruling was influenced by the understanding that denying the liberty to adopt to unmarried couples would violate the Equal Protection Clause of the 14th Amendment.
This decision was made in the context of a broader legal landscape where courts had to consider issues of privacy, civil rights, and discrimination, especially in relation to LGBTQ individuals and same-sex couples. Decisions like Lawrence vs. Texas discussed the right to privacy and equal protection in connection with sexual orientation, while federal and state laws pertaining to marriage and adoption have evolved to recognize various family arrangements, guided by principles of equal protection and the best interests of the child.