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The largest open database of local laws in the US (arxiv.org)
5 points by rao-v 105 days ago | hide | past | pdf | 1 comment on HN

In plain words: Local laws on zoning, noise, and licensing sit on websites meant for browsing, not bulk copying, so this project used text-recognition software to turn them into a collection organized by county. It contains codes from 9,239 cities and counties, nearly all that are publicly available.

Abstract · Freeing the Law with LOCUS: A Local Ordinance Corpus for the United States

Progress in legal AI increasingly depends on access to authoritative legal text at scale. Yet one of the most consequential layers of American law remains largely absent from existing machine-readable corpora: local ordinances. Local codes govern zoning, housing, business licensing, public health, noise, animal control, and many other domains of everyday regulation, but they are fragmented across vendor platforms designed for human browsing rather than bulk research access. We introduce LOCUS - the Local Ordinance Corpus for the United States - a comprehensive corpus and county-harmonized access layer for U.S. municipal and county ordinance codes. The raw corpus, available for release to researchers, represents nearly all publicly available municipal and county ordinance codes. The resulting raw corpus contains codes from 9,239 cities and counties. A smaller county-harmonized LOCUS access layer provides coverage for the largest 2,309 of 3,144 U.S. counties, accounting for a majority of the population. We use OCR to handle the myriad of document formats that have kept the law from being a public resource. We release the corpus with coverage metadata to support reproducibility, downstream legal AI research, and the incremental expansion of machine-readable access to local law. We train a collection of ModernBERT-based classifiers and scorers to facilitate analyzing U.S. local law among several dimensions, such as opacity and paternalism, that have not previously been studied at this scale. LOCUS-v1 and its derivative models are available at: https://huggingface.co/datasets/LocalLaws/LOCUS-v1

Denis Peskoff, Joe Barrow, Christopher Vu, Diag Davenport
arXiv:2606.19334 · cs.CL, cs.CY, cs.LG · submitted Jun 17, 2026
abstract · pdf · html · 14 pages, 6 figures

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A couple of Berkeley academics compiled a giant corpus of local laws and ordinances and classified them in various ways.

Unfortunately, they don't seem to have cleanly linked each ordinance to its source, so I'm not entirely sure it's as useful as it could be.