SRPA was created on May 27, 1934 by the Department of War after the United States government acknowledged the existence of the Chimera. The organization was tasked with finding ways to combat the Chimera, ranging from their experiments to find a vaccine for the Chimeran virus to creating new weapons and technology (mostly re-engineered from captured Chimeran technology) to directly combating the Chimeran threat. SRPA was also responsible for extracting Dr. Fyodor Malikov from Russia and recruited him into their organization based on his foreknowledge on the Chimera and his experiments on the Cloven.
In 1950, SRPA funded the creation of Project Abraham with the purpose of creating a special operations task force that is immune to the Chimeran virus. These surviving soldiers would be known as the Sentinels. It was during Project Abraham that test subject Jordan Adam Shepherd was inadvertently transformed into the Chimeran entity known as Daedalus. SRPA confined Daedalus before his escape on July 15, 1951.
SRPA also created a specialized network, known as SrpaNet, that was used for storing and relaying important files and documents relating to SRPA projects. The organization was also responsible for the development of the fission bomb and research of recovered Gray Tech components under Project Prometheus.
SRPA (although unnamed) conducted several clandestine Black Ops operations in Chimera-occupied Britain in observing the Chimera. The SRPA held a high priority extraction of Nathan Hale after intercepting British radio indicated his survival. After the destruction of the London Chimeran tower, SRPA Black Ops apprehended Hale.
Following Hale's extraction conducted by Major Richard Blake and being transferred to be process in SRPA Station Igloo in Iceland, Chimeran forces made a sudden attack on the facility. It is heavily presume that Daedalus was possibly responsible in being able to contact the Chimera in order to free him. Following Daedalus' escape, SRPA inducted Hale to the Sentinel Program and played an integral role in defending the United States and abroad.
During the invasion of America by the Chimeran fleet in May 1953, SRPA desperately attempted to stop Daedalus from activating the tower network in America. Ultimately, many SPRA personnel were killed throughout the invasion after a botched mission in attacking the Holar Tower in Holar, Iceland.
After the Liberty Defense Perimeter fell, SRPA made a last ditch assault on destroying the Chimeran fleet and ceasing Daedalus' plans over the Chicxulub crater in Operation Black Eden on June 26, 1953. The operation succeeded, but the outcome only inadvertently created a wormhole to the Chimera's homeworld.
The events transpired at the Chicxulub crater revealed that the explosion caused by the fission bomb inadvertently created an energy surge in the Chimeran tower network, creating the wormhole above New York City that leads directly to the Chimera's homeworld and being maintained by the city's hub tower. In response, SRPA launched a large assault on New York in an attempt to destroy the Chimeran tower and closing the portal, but were ultimately repelled and crushed by the large concentration of Chimeran forces defending the hub tower.
In the Infected storyline, SRPA recruited James Grayson as a Sentinel.
Prior to the Chimeran attack on New York City, SRPA researcher Richard Gorrell was conducting a classified experiment that was an attempt to control the Chimera through Grey Tech technology, which was known as Project Phoenix, stationed at Station Kali on Ellis Island. Gorrell and Project Phoenix was met with resistance from the U.S. military establishment and citing it as costly and "ethically reprehensible." Gorrell went rogue and continued Project Phoenix during the invasion in which he took advantage in manipulating the Chimera in abducting humans to be harvested to constructing an incomplete Leviathan, which Gorrell intended to control through Grey Tech devices. Gorrell's plot was foiled by Tom Riley, who he then killed the scientist.
- Fyodor Malikov - Biological Physician, created the Cloven and the Sentinels.
- Arthur L. Pratt - General of the United States Army.
- Robert Crowe - Senator.
- Julia Cathcart
- Richard P. Feynman
- Willard Libby - Physical chemist, developed radiocarbon dating.
- Howard Nash
- J. Robert Oppenheimer - Physicist, lead the creation of a highly enriched fission bomb.
- Martin Ortiz - Physician
Medical and Psychology
- Cassandra Aklin - Psychiatrist
- Henry Carter - Physician
- George Hopper - Physician
- Frederick Jean - Physician
- Percy Kabeck - Physician
- Anna Keegan - Physician
- Alan McKenzie - Psychiatrist
- Oscar Villamizar - Physician
Executive and Administration
- Lyle K. Parsons - Executive Director
Each SRPA base is unique in its own way, such as being a underwater base, but are commonly include with underground garage/hangar bays for aircraft and vehicles. In each SRPA base, Tac-Com directs all SRPA para-military actions including black ops and Sentinels' missions. Subsurface levels are dedicated to administration, medical, and food services. Living quarters being located deeper underground, and protected by a matrix of pathways in which pre-positioned explosives offered a defense against underground attacks, such as being breached by Chimeran Burrowers.
- SRPA 2 (Springfield, Illinois) - Mention to have an inhibitor station, and was attacked by Chimeran forces, but survived the attack while losing half of the base.
- SRPA 3 (San Francisco, California) - A coastal, underwater base that came under attack during the initial Chimeran invasion on May 15, 1953. Presumably lost during the attack.
- SRPA 4 - The base was destroyed after the fall of the Liberty Defense Perimeter, but not before completing a prototype fission bomb which was used in Operation Black Eden.
- SRPA 5 - Was station by Dr. Willard Libby, who used his method of radiocarbon dating on a recovered Gray Tech component.
- SRPA 6 (Valentine, Nebraska) - Underground base located near the original site of Fort Niobrara. Built in 1934, the base is noted for having its unearth debris during its construction phase used for building a 50 ft. wall surrounding the base. In response to SRPA Directive 1140.09, a moat is also built around the base that could be flooded with Avgas and set it on fire should it become necessary.
- SRPA 7 (Boulder, Colorado) - Formerly the site of Project Prometheus after a severe, experimental accident with the Gray Tech components.
- SRPA 8 (Cincinnati, Ohio) - Housed the Crihkhorn Lab, which discovered that Chimeran tissue was non-terrestrial, and in fact, possibly non-solar in origin. 
- SRPA 11 (Black Rock Desert, Nevada) - Relocated site of Project Prometheus.
- SRPA 12 (Atlanta, Georgia) - Noted for receiving a distress message from survivors in Savannah, Georgia.
- SRPA NT (Alaska) - Site of Project Abraham. Research site of the fission bomb.
- SRPA Substation Kappa - Destroyed during Operation Icarus, allegedly due to Joseph Capelli's insubordinate actions.
- SRPA Research Station Igloo (Iceland) - Contained Daedalus since July 10th, 1951. Later came under attacked by Chimeran forces on July 15th, 1951 in which allowing Daedalus to escape. It was soon abandoned and used by the Chimera as a base instead.
- SRPA Station Kali (Ellis Island, New York) - Served as SPRA Laboratory of Project Abraham. Abandoned and completely overrun when the Chimera invaded the United States on August 14, 1951.
- Research Station Genesis (Bryce Canyon, Utah) - Research site that studies Bryce Canyon's Chimeran Tower, and as well in other subjects relating to the Chimera. Station Genesis became under attack and overrun by the Chimera during the Chimeran invasion in mid-1953.
- Denver Federal Center (Denver, Colorado) - SRPA Command Base for Sentinel missions in the northern United States. It was also served as a Sentinel hospital. Presumably destroyed when the Chimera attacked Denver.
- 3380 Clarendon Blvd, 8th Floor (Arlington, Virginia) - Contained to all official documents, such as Sentinel dossiers as well as SRPA regulation sheets, are created.
- SRPA was originally to be called the Special Research Projects Agency as seen in various files in Project Abraham and the America First - America Only newspapers.
- It seems that the SRPA logo can be found on almost any piece of human technology. Whether it be American, British, or Maquis. Concept arts indicate that the SRPA logo is designed for a unified human faction at first.
- SRPA's black ops members have a tattoo of a skull with a sword underneath the skull seen on Mick Cutler, who was kicked out of SRPA after serving in the unit.
- Pre-alpha concept arts show that the SRPA was going to have a fortified compound in England and employ human-piloted reverse-engineered walking tanks.