But on Thursday, about a month after Mr. Trump publicly criticized the private construction effort, federal prosecutors in New York unveiled an indictment accusing the fund-raising campaign of ties to a scheme that "defrauded hundreds of thousands of donors."WASHINGTON — As President Trump fumed in 2018 over the progress his government was making on a border wall, an Air Force veteran's pro-wall GoFundMe page would transform into a separate project, funded by private donations and guided by former Trump advisers, including Stephen K. Bannon.

Frustrated over the delays in Mr. Trump's signature campaign promise, Brian Kolfage's group, We Build the Wall, raised more than $20 million in weeks, largely on the promise of sidestepping the legal and political obstacles to building a border wall by using private funding to construct it on privately owned land.