The Trump administration is pushing ahead with the purchase of warehouses it plans to convert into immigration jails in what could be the largest expansion of such detention capacity in US history. The warehouses, many of which originally were designed and marketed as e-commerce distribution facilities, represent a significant pivot for the administration’s $45 billion immigration detention buildout.

The Trump administration’s push to make 3,000 immigration arrests per day — and its insistence that those adjudicating their cases do so from detention — has created an intense demand for jail space. It has gone through multiple iterations of plans to massively expand its detention capacity.

Last year, it relied on tent camps constructed in remote places like the Florida Everglades and an Army base in Texas. Little has been publicly shared about ICE’s plans for the new detention centers in small towns and cities across the country. The 23 proposed sites would range in size from 500 to 9,500 beds. If completed as planned, the larger facilities would be some of the biggest detention centers of any kind in the country.

For example, the 9,500-bed facility ICE is planning for Hutchins, Texas, could fit the entire average daily jail population of Dallas County with thousands of beds to spare. To reach its goal of deporting 1 million people a year, the Trump administration has said it needs more than 100,000 detention beds. Currently, there are more than 73,000 people in ICE custody, a record. The new sites could give the agency an additional 76,500 beds, according to documents shared with Bloomberg News.

To fill all of them, the administration would have to expand immigration arrests beyond what it is already doing, said Emma Winger, deputy legal director at the American Immigration Council. At least six people have died nationwide since Trump’s crackdown began.

Local governments are limited in what they can do to prevent ICE from opening and operating a detention facility, even if it doesn’t meet local zoning requirements. That’s because federal actions typically supersede local rules, though it can become more complicated when private companies are doing things on behalf of the federal government.