Question: Which booster was used to send the 1st American into orbit?

full_context: Document 1: Apollo Command/Service Module: The Command/Service Module (CSM) was one of two spacecraft, along with the Lunar Module, used for the United States Apollo program which landed astronauts on the Moon. It was built for NASA by North American Aviation. It was launched by itself on three suborbital and low Earth orbit Apollo test missions using the Saturn IB launch vehicle. It was also launched twelve times on the larger Saturn V launch vehicle, both by itself and with the Lunar Module. It made a total of nine manned flights to the Moon aboard the Saturn V.
Document 2: Apollo 1: Apollo 1, initially designated AS-204, was the first manned mission of the United States Apollo program, which had as its ultimate goal a manned lunar landing. The low Earth orbital test of the Apollo Command/Service Module never made its target launch date of February 21, 1967. A cabin fire during a launch rehearsal test on January 27 at Cape Kennedy Air Force Station Launch Complex 34 killed all three crew members—Command Pilot Virgil I. "Gus" Grissom, Senior Pilot Edward H. White II, and Pilot Roger B. Chaffee—and destroyed the Command Module (CM). The name "Apollo 1", chosen by the crew, was officially retired by NASA in commemoration of them on April 24, 1967.
Document 3: Lunar Escape Systems: Lunar Escape Systems (LESS) were a series of emergency vehicles designed for never-flown long-duration Apollo missions. Because these missions were even more hypothetical than the planned cancelled Apollo missions, the designs were never constructed. This concept was an outgrowth of the Lunar Flying Vehicle designed by Bell Aerospace (a lunar surface mobility design that was cancelled in favor of the less risky Lunar Rover).
Document 4: Space Shuttle Columbia: Space Shuttle "Columbia" (Orbiter Vehicle Designation: OV-102) was the first space-rated orbiter in NASA's Space Shuttle fleet. It launched for the first time on mission STS-1 on April 12, 1981, the first flight of the Space Shuttle program. Over 22 years of service it completed 27 missions before disintegrating during re-entry near the end of its 28th mission, STS-107 on February 1, 2003, resulting in the deaths of all seven crew members.
Document 5: United States Senate election in Ohio, 1992: The 1992 United States Senate election in Ohio was held on November 3, 1992. Incumbent Democratic U.S. Senator John Glenn won re-election to a fourth term, coinciding with Bill Clinton's narrow win during the presidential election. Glenn's voting percentage of 51% represented the worst performance of his four runs for the Senate, likely due to the presence of third-party candidate Martha Grevatt of the far-left Workers World Party. As of 2016, this is the last time the Democrats have won the Class 3 Senate Seat from Ohio.
Document 6: Gus Grissom: Lieutenant Colonel Virgil Ivan "Gus" Grissom (April 3, 1926 – January 27, 1967) was one of the original NASA Project Mercury astronauts, a United States Air Force test pilot, and a mechanical engineer. He was the second American to fly in space, and the first member of the NASA Astronaut Corps to fly in space twice.
Document 7: T. J. O'Malley: Thomas Joseph O'Malley (October 15, 1915 – November 6, 2009), better known as T. J. O'Malley, was an Irish-American aerospace engineer who, as chief test conductor for the Convair division of General Dynamics, was responsible for pushing the button on February 20, 1962 launching the Mercury-Atlas 6 space flight carrying astronaut John Glenn, the first American in orbit. Five years later, NASA asked North American Aviation to hire him as director of launch operations to help get the Apollo program back on track after the Apollo 1 command module fire on the launch pad killed three astronauts. O'Malley continued to play a leadership role in the United States' space program through the first space shuttle launch in 1981.
Document 8: Michael Collins (astronaut): Michael Collins (born October 31, 1930) (Major General, USAF, Ret.), is an American former astronaut and test pilot. Selected as part of the third group of fourteen astronauts in 1963, he flew into space twice. His first spaceflight was on Gemini 10, in which he and Command Pilot John Young performed two rendezvous with different spacecraft and Collins undertook two extra-vehicular activities (EVAs). His second spaceflight was as the Command Module Pilot for Apollo 11. While he stayed in orbit around the Moon, Neil Armstrong and Buzz Aldrin left in the Lunar Module to make the first manned landing on its surface. He is one of 24 people to have flown to the Moon.
Document 9: John Glenn: John Herschel Glenn Jr. (July 18, 1921 – December 8, 2016) was a United States Marine Corps aviator, engineer, astronaut, and United States Senator from Ohio. In 1962 he became the first American to orbit the Earth, circling it three times.
Document 10: Wally Schirra: Walter Marty "Wally" Schirra Jr. (March 12, 1923 – May 3, 2007), (CAPT, USN), was an American naval officer and aviator, aeronautical engineer, test pilot, and one of the original seven astronauts chosen for Project Mercury, United States first effort to put humans in space. He flew the six-orbit, nine-hour Mercury-Atlas 8 mission on October 3, 1962, becoming the fifth American, and the ninth human, to ride a rocket into space. In the two-man Gemini program, he achieved the first space rendezvous, station-keeping his Gemini 6A spacecraft within 1 ft of the sister Gemini 7 spacecraft in December 1965. In October 1968, he commanded Apollo 7, an 11-day low Earth orbit shakedown test of the three-man Apollo Command/Service Module. He was the first person to go into space three times, and the only person to have flown in Mercury, Gemini, and Apollo, logging a total of 295 hours and 15 minutes in space. He retired from the U.S. Navy at the rank of Captain and from NASA after his Apollo flight, becoming a consultant to CBS News for its coverage of the subsequent Apollo flights. He joined Walter Cronkite as co-anchor for the seven Moon landing missions.
Document 11: Orion abort modes: NASA's newest spacecraft, the Orion Multi-Purpose Crew Vehicle (MPCV), will be the first American spacecraft since Project Apollo to use an escape system in the event of a launch abort, something its predecessor, the Space Shuttle, had for only its first four orbital test flights in 1981-1982. Like the Apollo Command-Service Module (CSM), the Orion CEV will use the Launch escape system (LES), a solid-fueled tractor rocket that will be able to pull the Orion crew module away from a malfunctioning Space Launch System (SLS) rocket during the initial launch phase. Based on the launch escape system found on the Soviet/Russian Soyuz spacecraft, the LAS, designed and manufactured by ATK for the Orion CEV, will be larger than the Soyuz version and will have more thrust than the Atlas 109-D booster that carried astronaut John Glenn into orbit in 1962.
Document 12: Apollo Lunar Module: The Apollo Lunar Module (LM), originally designated the Lunar Excursion Module (LEM), was the lander portion of the Apollo spacecraft built for the US Apollo program by Grumman Aircraft to carry a crew of two from lunar orbit to the surface and back. Designed for lunar orbit rendezvous, it consisted of an ascent stage and descent stage, and was ferried to lunar orbit by its companion Command/Service Module (CSM), a separate spacecraft of approximately twice its mass, which also took the astronauts home to Earth. After completing its mission, the LM was discarded. It was capable of operation only in outer space; structurally and aerodynamically it was incapable of flight through the Earth's atmosphere. The Lunar Module was the first manned spacecraft to operate exclusively in the airless vacuum of space. It was the first, and to date only, crewed vehicle to land on a natural object in the solar system other than the Earth.
Document 13: Gordon Cooper: Leroy Gordon "Gordo" Cooper Jr. (March 6, 1927 – October 4, 2004), (Col, USAF), better known as Gordon Cooper, was an American aerospace engineer, test pilot, United States Air Force pilot, and one of the seven original astronauts in Project Mercury, the first manned space program of the United States.
Document 14: First Orbit: First Orbit is a feature-length, experimental documentary film about Vostok 1, the first manned space flight around the Earth. By matching the orbit of the International Space Station to that of Vostok 1 as closely as possible, in terms of ground track and time of day, documentary filmmaker Christopher Riley and European Space Agency astronaut Paolo Nespoli were able to film the view that Yuri Gagarin saw on his pioneering orbital space flight. This new footage was cut together with the original Vostok 1 mission audio recordings sourced from the Russian State Archive of Scientific and
Document 15: Saturn V: The Saturn V (spoken as "Saturn five") was an American human-rated expendable rocket used by NASA between 1967 and 1973. The three-stage liquid-fueled super heavy-lift launch vehicle was developed to support the Apollo program for human exploration of the Moon and was later used to launch Skylab, the first American space station. The Saturn V was launched 13 times from the Kennedy Space Center in Florida with no loss of crew or payload. As of 2017,  the Saturn V remains the tallest, heaviest, and most powerful (highest total impulse) rocket ever brought to operational status, and holds records for the heaviest payload launched and largest payload capacity to low Earth orbit (LEO) of 140000 kg , which included the third stage and unburned propellant needed to send the Apollo Command/Service Module and Lunar Module to the Moon.
ground_truth: Atlas 109-D booster