[4] He received his episcopal consecration on the following June 29 from Spellman, with Bishops Joseph Francis Flannelly and James Griffiths serving as co-consecrators, at St. Patrick's Cathedral.[4] Maguire assumed as his episcopal motto: Tutam Reclude Semitam (Latin: "Disclose a way of life free of danger"), taken from the hymn "Praeclara custos virginum" (For the Blessed Virgin Mary).[3] Known as a champion for racial justice, Maguire encouraged New York Catholics to participate in the 1963 March on Washington for Jobs and Freedom, during which Doctor Martin Luther King Jr. delivered his historic "I Have a Dream" speech.[6] Following Spellman's death in December 1967, Maguire was elected by the archdiocesan board of consultors to serve as apostolic administrator of New York until the pope named a new archbishop.[7] In the interim, he was mentioned as a top candidate to fill the vacant post, but Paul VI ultimately appointed Auxiliary Bishop Terence Cooke as archbishop in March 1968.