WESLACO, Texas -- In the archives of local institutions, Juan Aranda's life is firmly rooted in this small south Texas town.

His birth certificate says he was delivered unto Weslaco 38 years ago, and church records say he was baptized here soon after. School files list him as a student in the local district from kindergarten through high school, and voter rolls show he votes for president here.

But to the U.S. State Department, all that black and white looks a lot like gray. It recently refused to issue Mr. Aranda a passport; the government isn't sure he's an American.

"I never imagined my U.S. citizenship would be questioned," says the manager at a water company. "I've lived here since the day I was born."

The problem is that Mr. Aranda was delivered by a midwife at a private home. Parteras, Spanish for midwives, have been part of life in Hidalgo and Cameron counties along the border with Mexico from the time of the Texas Republic and before. But in the early 1990s, dozens of midwives were convicted of forging U.S. birth certificates for about 15,000 children born in Mexico as far back as the 1960s.