<p>Data centers form the physical backbone of the digital economy, yet their integration into the US urban fabric remains poorly understood. Here we demonstrate that data centers are an overwhelmingly urban phenomenon, with 97.5% of facilities situated in metropolitan and micropolitan statistical areas, challenging the prevailing narratives of ‘rural cloud expansion’. Their spatial logic is driven by the nameplate capacity of local power plants and, to a lesser extent, by broadband quality, retired coal plants, information technology employment and natural hazards. The reliance on local power systems embeds data center siting within state-level energy generation patterns, amplifying geographic contrasts in the sustainability of the data center boom. Population-based projections of data centers’ growth indicate that the digital transition will reinforce existing urban hierarchies rather than catalyze decentralization. These findings suggest a path-dependent evolution linked to existing infrastructure and fossil fuel industrial legacy, posing considerable challenges to urban livability.</p>