Prosecutors say 65-year-old Austin Winther of Philadelphia tried to lure a supposed Idaho woman and her 13-year-old daughter to travel to Pennsylvania in March 2011 for a sexual tryst.
An undercover investigator was posing as the mother and daughter.
Winther pleaded guilty in November to an interstate sex charge and four obscenity counts.
Before his sentencing Friday, Winther apologized for conduct he said "appalled and sickened" him.
U.S. District Judge Jan DuBois also ordered him to serve 10 years of supervised release and register as a sex offender upon his release from prison.
Winther taught at Rider's Graduate School of Education in Lawrenceville, N.J., from 2005 until 2009.
