Question: Where is the largest ROTC program in the United States located?
Context: Colonel David E. Pergrin (26 July 1917 – 7 April 2012) was commanding officer of the 291st Engineer Combat Battalion of the United States Army during World War II.  Before the war he earned an engineering degree at Pennsylvania State University, graduating in 1940.  While at Penn State he participated in the ROTC program.  In addition, Pergrin played on the university's football team, was elected to the Tau Beta Pi and Chi Epsilon engineering honor societies, and was senior class president.  Before graduation he was voted Outstanding Non-Fraternity senior.  In his role as senior class president, he presented the university with the Class of 1940 gift - the Nittany Lion Shrine, a 14-ton limestone monument symbolizing the Penn State tradition.  However, the monument was not officially dedicated until 1942. The Army Reserve Officers' Training Corps (ROTC, AROTC, or SROTC) is the United States Army component of the Reserve Officers' Training Corps.  It is the largest ROTC program, with 20,000 ROTC cadets in 273 ROTC programs at major universities throughout the United States.  These schools are categoriezed as Military Colleges (MC), Military Junior Colleges (MJC) and Civilian Colleges (CC). New Mexico Military Institute (N.M.M.I.) is a state-supported educational institution located in Roswell, New Mexico, United States.  One of four military junior colleges in the United States, it is the only state-supported military college located in the western United States.  NMMI includes a college preparatory four-year high school and a two-year junior college.  Students who attend NMMI are referred to as Cadets.  NMMI is the only state-supported co-educational college preparatory military boarding high school (grades 9–12) and junior college in the United States.  Academic school years begin with about 900 and 980 cadets enrolled.  The school's 2-year Army ROTC Early Commissioning Program (ECP) commissions approximately 30 cadets each year as US Army 2nd Lieutenants, and almost 100 cadets each year go to one of the five major United States Service academies. A direct commission officer (DCO) is a United States uniformed officer who has received a commission without the typical prerequisites for achieving a commission, such as a four-year service academy, a four-year or two-year college ROTC program, or one of the officer candidate school or officer training school programs, the latter OCS/OTS programs typically slightly over three months in length. The 5th Reserve Officers' Training Corps Brigade is an Army Reserve Officers' Training Corps brigade based at Fort Sam Houston, Texas. Reserve Officers' Training Corps () in the Republic of China (Taiwan) was first proposed by the Ministry of National Defense in September 1995 and has been in operation since 1997 or 1999.  Other sources mention that an ROTC program was already active in Taiwan in the 1960s.  ROTC in Taiwan is based on the Reserve Officers' Training Corps program of the United States.  The proposed training regimen consisted of three to four additional hours of military courses each week aside from university classes.  During the winter vacation, students were to attend a one or two-week boot camp and in the summer, they would undergo six weeks of military training. Brigadier General Thomas Hemingway is an American military lawyer who has served as a legal advisor to the Office of Military Commissions.  Thomas Hemingway was a distinguished graduate of the Air Force ROTC program, was commissioned as a second lieutenant in November 1962 after earning his undergraduate degree at Willamette University.  Upon graduation, he took an educational delay and earned his doctor of jurisprudence in 1965 at Willamette University College of Law.  Hemingway entered active service in November 1965.  He has also been an associate professor of law at the United States Air Force Academy and a senior judge on the Air Force Court of Military Review.  He is a current member of the state bar in Oregon and the District of Columbia, and has been admitted to practice before the U.S. Court of Federal Claims, the U.S. Court of Appeals for the Federal Circuit and the Supreme Court of the United States.  He retired from active service in October 1996.  General Hemingway was recalled to active service in August 2003 to fill the position as Legal Adviser to the Convening Authority in the Department of Defense Office of Military Commissions, Washington, D.C. General. The Marine Military Academy is a private college preparatory academy located in Harlingen, Texas, offering a college preparatory curriculum for boys in grades 8–12 plus one year of post-graduate study.  The school was founded in 1965.  Its traditions and ideals are inspired by the United States Marine Corps, but the school is not affiliated with the United States Marine Corps except through its Junior ROTC program. The Temple University Army Reserve Officer's Training Corps is an officer commissioning program for the United States Army for students attending Temple University and neighboring colleges.  The program commissions officers through Army ROTC.  Temple University's ROTC Battalion is one of the many schools part of the 2nd Reserve Officers' Training Corps Brigade, which is headquartered at Fort Dix.  Temple University students who wish to commission as officers into the United States Navy or the United States Marine Corps participate in the Navy ROTC program at the University of Pennsylvania.  Those wishing to earn an officer's commission in the United States Air Force participate in the Air Force ROTC program at Saint Joseph's University. Charles Albert "Chuck" Horner (born October 19, 1936) is a retired USAF Four-Star General.  He was born in Davenport, Iowa and attended the University of Iowa, as part of the Air Force ROTC program.  On June 13, 1958, Horner was commissioned into the Air Force Reserve.  During the Vietnam War, he flew in combat as a Wild Weasel pilot and received the Silver Star.  During Operation Desert Shield and Operation Desert Storm, he commanded the American aerial forces, as well as those of the American allies.  During the Desert Shield phase of the conflict, Horner briefly served as Commander-in-Chief — Forward of U.S. Central Command; while General Schwarzkopf was still in the United States.  He currently serves on the board of directors for the US Institute of Peace.
Answer: Fort Sam Houston, Texas