Members of Congress took small-business loans — and the full extent is unknown

At least four members of Congress have reaped benefits in some way from the half-trillion-dollar small-business loan program they helped create.

And no one knows how many more there could be.

It’s a bipartisan group of lawmakers who have acknowledged close ties to companies that have received loans from the program — businesses that are either run by their families or employ their spouse as a senior executive.

Republicans on the list include Rep. Roger Williams of Texas, a wealthy businessman who owns auto dealerships, body shops and car washes,...