Clinical Trial Registry History R package cthist version 2.1.12 Retrieves historical versions of clinical trial registry entries from <https://ClinicalTrials.gov>. Package functionality and implementation for v 1.0.0 is documented in Carlisle (2022) <DOI:10.1371/journal.pone.0270909>. Software Imports: assertthat, dplyr, httr, jsonlite, lubridate, magrittr, readr, rlang, stringr, tibble, purrr, tidyr Suggests: testthat (>= 3.0.0) Benjamin Gregory Carlisle <murph@bgcarlisle.com> Comprehensive R Archive Network (CRAN) Benjamin Gregory Carlisle [aut, cre] (ORCID: <https://orcid.org/0000-0001-8975-0649>) AGPL (>= 3) 2025-08-29 application/tgz https://CRAN.R-project.org/package=cthist doi:10.32614/CRAN.package.cthist