This article considers the problem of popular, collectively organized political action in the context of the abolition movement of the slave trade (1788–1807). Various primary sources, a petition, a trade directory, church records, and a self-built historic GIS are used to locate petitioners for abolition in the social fabric of Manchester. Through matching and computational experiments the article highlights which social structural forces led individuals to support the abolition movement by signing a petition. Specifically, gathering places that were historically involved in the movement, as well as those that housed traveling merchants from communities with successful abolitionist petitions from preceding campaigns shaped abolitionist petitioning—and the impact of these institutions remained important over and above family ties, active religious congregations, and the occupational groups. The article gives a new understanding of the role that early industrialization played in the abolition movement, building it from the bottom up, forging cohesion within and across communities through local institutions, rather than creating new boundaries and divides through processes of class formation.