A former elected official in Arizona has pleaded guilty to running an illegal multi-state adoption scheme.
Paul Petersen unlawfully placed over 70 babies up for adoption in Arizona, Arkansas and Utah since 2014, prosecutors said.
He will serve 74 months in federal prison, the first of three likely punishments.
The adoptions used pregnant women from the Republic of the Marshall Islands, a Pacific Ocean sovereign state.
In his private-sector career as an adoption attorney, Mr Petersen flew several pregnant Marshallese women into the country to have their babies on US soil, which is forbidden by the Compact of Free Association, an agreement that binds the two countries.
He charged American families as much as $40,000 (£29,930) to adopt the newborn children, allegedly claiming the money would cover medical expenses and legal fees, according to the Arizona Republic newspaper.
He offered the mothers $10,000 upon childbirth. He also made travel arrangements and held them at his properties in their prenatal months, often confining several mothers to a bare room and even confiscating some of their passports.
Mr Petersen and his associates also submitted fraudulent documents to illegally sign the foreigners up for government-funded health coverage.
At the sentencing, he said he had treated those "on all sides of the adoption, with respect" and apologised to birth mothers who may have felt harmed.
Prosecutors slammed his actions as a "get-rich-quick scheme".
According to court documents, he used the funds from the illicit adoption scheme to finance cross-country travel, luxury cars and several vacation homes.
"He subverted what should be a joyous time for everyone into a baby-selling enterprise," said federal judge Timothy Brooks, who imposed the sentence on 1 December.
"The conduct Mr Petersen engaged in violates public policy. We don't sell babies. That is the public policy of the United States of America."
A member of the Church of Jesus Christ of Latter-day Saints, Mr Petersen became steeped in the Marshallese language and culture during a mission trip there in 1998. Prosecutors alleged he took advantage of mostly poor and uneducated women, coaxing them with an amount of money they could not refuse.
Since his indictment last October, he has been disbarred and forced to resign from the elected position he had held for six year - in Maricopa County, Arizona - as the county assessor, a person responsible for determining property values.
In addition to his federal sentence, he may now face additional state charges next month, in Arizona and Utah. The convictions could add as many as 30 years to his current sentence.