Final answer:
The Comstock Law, passed in 1873, was the legislation that made the mailing of obscene material a felony, aligning with societal efforts to regulate morality and vice.
Step-by-step explanation:
The legislation passed in 1873 that made the mailing of material considered to be obscene a felony is known as the Comstock Law. This law was part of a larger societal drive to impose moral standards and combat vice in society.
The Comstock Law was named after Anthony Comstock, a noted anti-obscenity crusader, and its primary purpose was to stem the tide of "lewd and lascivious literature" available to the public.
Although the immediate target was the distribution of obscene material through the mail, the implications of the law were far-reaching in terms of censorship and moral regulation.