The concept of Public Interest Litigation originated in

The concept of Public Interest Litigation (PIL) originated and developed in the United States in the 1960s. It emerged as a means to provide legal representation and access to justice for previously unrepresented groups and interests, expanding standing rules to allow public‑spirited litigants to raise collective or diffuse grievances on behalf of disadvantaged persons. The terminology and practice were later adapted in other jurisdictions—India adopting PIL procedures in the early 1980s as part of a broader judicial‑activism movement—but the doctrinal and historical roots trace back to the US mid‑20th century experience [2].

Sources

1. [1] Laxmikanth, M. Indian Polity. 7th ed., McGraw Hill. > Chapter 29: Public Interest Litigation > Public Interest Litigation > p. 309
2. [2] https://egyankosh.ac.in/bitstream/123456789/17195/1/Unit-3.pdf