The transfers began in the late morning and stretched nearly 40 minutes, finishing after noon. Time and again, service members in varying shades of green fatigues carried flag-draped transfer cases down the ramp of the transport, which faced Air Force One on the runway. First came the Army, then the Marines, then the Navy. The carry teams, as they are called, worked in three-minute cycles, marching before a host of dignitaries including the president, the secretaries of state and defense, and several top military brass. They carried the remains from the transport and lifted them through the back cargo doors of four gray vans.

The president stood with his hand over his heart as they passed by. When sets of Marines returned to the belly of the C-17, hands empty, to retrieve the next set of remains, Mr. Biden widened his stance and clasped his hands by his belt or behind his back. Often he bowed his head with his eyes squeezed shut, as if in prayer.

Across from him sat rows of family members of the fallen, so many of them that the Dover base could not house them all in its rooms built specially for next of kin.

The fallen service members returning Sunday to Dover were Marine Corps Staff Sgt. Darin T. Hoover, 31, of Salt Lake City; Marine Corps Sgt. Johanny Rosario Pichardo, 25, of Lawrence, Mass.; Marine Corps Sgt. Nicole L. Gee, 23, of Sacramento, Calif.; Marine Corps Cpl. Hunter Lopez, 22, of Indio, Calif.; Marine Corps Cpl. Daegan W. Page, 23, of Omaha; Marine Corps Cpl. Humberto A. Sanchez, 22, of Logansport, Ind.; Marine Corps Lance Cpl. David L. Espinoza, 20, of Rio Bravo, Texas; Marine Corps Lance Cpl. Jared M. Schmitz, 20, of St. Charles, Mo.; Marine Corps Lance Cpl. Rylee J. McCollum, 20, of Jackson, Wyo.; Marine Corps Lance Cpl. Dylan R. Merola, 20, of Rancho Cucamonga, Calif.; Marine Corps Lance Cpl. Kareem M. Nikoui, 20, of Norco, Calif.; Navy Hospitalman Maxton W. Soviak, 22, of Berlin Heights, Ohio; and Army Staff Sgt. Ryan C. Knauss, 23, of Corryton, Tenn.

The president and the first lady, Jill Biden, met with the families of those service members midmorning on Sunday. They then participated in 13 transfers — 11 for families who chose to allow the news media to observe the remains of their loved ones returning home, and two for families who chose to keep their transfers private.