WASHINGTON — Pope Francis has named Archbishop Wilton Gregory of Atlanta as the new Roman Catholic archbishop of Washington, hoping to end a tumultuous period for a pivotal diocese whose recent leaders have been at the center of the church’s sexual abuse crisis in the United States.

Archbishop Gregory, 71, becomes the first African-American bishop to lead the archdiocese, a position that puts him to in line to become the country’s first African-American cardinal. He has led the archdiocese of Atlanta since 2005.

The archdiocese of Washington has been without an official leader for nearly six months, and the appointment replaces one of Pope Francis’ closest allies in the American church. Cardinal Donald Wuerl, who became archbishop of Washington in 2006, resigned in October after he was named in a Pennsylvania grand jury report that accused church officials of covering up sexual abuse.

Theodore E. McCarrick, a former cardinal and the archbishop of Washington before Cardinal Wuerl, was defrocked in February after church officials found him guilty of sexually abusing minors and adult seminarians over decades. It was the first time an American cardinal has been removed from the priesthood.