Joel Wright, 23, of Pontifical College Josephinum in Columbus, Ohio, was taken into custody after getting off a plane in San Diego, according to Immigration and Customs Enforcement.
According to authorities he had sent emails to an undercover federal agent posing as a travel guide, saying he wanted to adopt or purchase a girl under three in Tijuana, Mexico, for the purposes of sexual intercourse.
College spokesperson, Revd John Allen told the Columbus Dispatch the seminary was "shocked and saddened" at the "reprehensible" allegations.
Joel Wright has been expelled and will make his first court appearance on Monday.
