https://www.ars.usda.gov/midwest-area/madison-wi/vegetable-crops-research/docs/services#Carrot
This collection represents carrot breeding lines that were publicly released by the USDA from 1976 onwards.
Currently there are 50 accessions from this collection in CarrotOmics.
You can search for germplasm in this collection using the Germplasm Search by Collection page.