The U.S. celebrated saving foreign orphans. But thousands were left without citizenship, at risk of deportation, because of loopholes in American law.

Thousands of South Korean adoptees are looking to satisfy a raw, compelling urge that much of the world takes for granted: the search for identity. Rebecca Kimmel, one of them, has stumbled into a web of switched photos, made-up stories and false documents that erase the very identity she desperately wants to find.

Dozens of South Korean adoptees, many in tears, have responded to an investigation led by The Associated Press and documented by FRONTLINE on adoptions from South Korea. The investigation reported dubious child-gathering practices and fraudulent paperwork involving South Korea's foreign adoption program, which peaked in the 1970s and '80s.

Hundreds of thousands of South Korean children were adopted by families in the United States, Europe and Australia. Now adults, many have since discovered that their adoption paperwork was untrue, and their quest for accountability has spread far beyond South Korea’s borders to the Western countries that claimed them.

The stories of South Korean adoptees — who searched for their roots and realized they are not who they were told — have sparked a reckoning that is rocking the international adoption industry.