This article is a product of the first complete survey of British public representational monuments in the U.K. related to transatlantic slavery, available online at https://www.britishmonumentsrelatedtoslavery.net . Identifying over 900 monuments, it brings this survey to bear on current public and policy debates about such monuments' history, significance and meaning vis-à-vis slavery, art and heritage. Examining the monuments at scale, we identify the monuments' patterns of production and provide data-led answers to specific questions such as what Britain's most significant monumental legacies of slavery are; how enslaved people appear in British public monuments; and how this data might support rethinking these monuments.