The actively currated datasets are in the {mosaicData} R package.

Supplemental data for Lessons in Statistical Thinking

These have documentation in the {LSTbook} package, but the data themselves need to be load()ed as a URL. This is to keep the {LSTbook} package small by not including large datasets that are rarely used.

load("https://www.mosaic-web.org/go/datasets/natality_2014.rda")