The Permanent Subcommittee on Investigations (PSI), stood up in March 1941 as the "Truman Committee," is the oldest subcommittee of the United States Senate Committee on Homeland Security and Governmental Affairs (formerly the Committee on Government Operations).
The Truman Committee (itself successor to the Nye Committee 1934–1936) stood up from March 1941 to 1948, the Investigations Subcommittee of the Committee on Expenditures in Executive Departments took over two key aspects of the Truman Committee. First, Investigations Subcommittee took the Truman Committee's investigation of war contracts and procurement of the Hughes XF-11 reconnaissance aircraft and the Hughes H-4 Hercules flying boat (Spruce Goose). Second, the subcommittee also assumed responsibility for the records of the Truman Committee.
Under the chairmanship of Homer S. Ferguson of Michigan (1948) and Clyde R. Hoey of North Carolina (1949-1952), the Investigations Subcommittee of the Committee on Expenditures in Executive Departments held hearings on such matters as export control violations, for which Soviet spy William Remington was called in to testify; the trial of Nazi war criminal Ilse Koch; and the Mississippi Democratic Party's sale of postal jobs, which Mississippians from rural areas attested to purchasing. A much larger scandal erupted with the "5 percenters", so-called because these men, including Presidential aide Harry H. Vaughan, were accused of charging a 5% commission for their influence in securing government contracts. A legislative reform as a result of the hearings was a restriction of one year after leaving government employment before an attorney could practice law again before the government.
As news of war crimes during the Korean War unfolded, the Subcommittee on Korean War Atrocities was headed by Charles E. Potter, and began an investigation of the abuse and murder of prisoners of war such as forced marches, maltreatments, and the shooting and murdering of prisoners shortly after capture.
In the 83rd United States Congress, the subcommittee (now known as the Permanent Subcommittee on Investigations or PSI), under its new chairman, Joseph McCarthy of Wisconsin, greatly increased the number of investigations and number of witnesses called. His subcommittee held 169 hearings throughout 1953 and 1954. Of the 653 people called by the Committee during a 15-month period, 83 refused to answer questions about espionage and subversion on constitutional grounds and their names were made public. Nine additional witnesses invoked the Fifth Amendment to the United States Constitution in executive session and their names were not made public. Some of the 83 were working or had worked for the Army, the Navy, the Government Printing Office, the Department of the Treasury, the Office of War Information, the Office of Strategic Services, and the Department of Veterans Affairs. Others were or had been employed at the Federal Telecommunications Laboratories in New Jersey, the secret radar laboratories of the Army Signal Corps in New Jersey, and General Electric defense plants in Massachusetts and New York. Nineteen of the 83, including well known communist party members James S. Allen, Herbert Aptheker, and Earl Browder, were summoned because their writings were being carried in United States Information Agency libraries around the world.
The hearings also investigated such matters as communist infiltration of the United Nations; Korean War atrocities; and the transfer to the Soviet Union of occupation currency plates. From December 1952 to July 1953, Robert Kennedy was an assistant counsel of PSI.
In April 1954, McCarthy's exchange of charges with Secretary of the Army Robert T. Stevens led to the appointment of a special subcommittee of the PSI to investigate the charges. Chaired by Karl E. Mundt of South Dakota, the proceedings became known as the Army–McCarthy hearings.
From 1955 until 1972, John Little McClellan of Arkansas chaired the PSI. McClellan continued extensive hearings of the Army Signal Corps at Fort Monmouth, New Jersey, and added new inquiries relating to communist activities in the United States and to business activities and alleged improper activities by Eisenhower Administration appointees and political associates. In the 86th Congress (1957), members of the Subcommittee were joined by Members of the Committee on Labor and Public Welfare on a special committee (the Select Committee on Improper Activities in Labor and Management) to investigate labor racketeering. Chaired by Senator McClellan and staffed by Robert F. Kennedy, the Subcommittee’s chief counsel, and other staff members, this special committee directed much of its attention to criminal influence over the International Brotherhood of Teamsters, most famously calling Teamsters’ leaders Dave Beck and Jimmy Hoffa to testify. The televised hearings of the special committee also introduced Senators Barry Goldwater and John F. Kennedy to the nation, as well as leading to passage of the Labor Management Reporting and Disclosure Act.
After the select committee expired in 1960, the PSI continued to investigate labor racketeering and other labor-related matters. From 1961 through 1968, it also investigated gambling and organized crime in which Joseph Valachi testified about the activities of the Sicilian Mafia, the Billie Sol Estes case, irregularities in missile procurement, procurement of the General Dynamics F-111 Aardvark fighter plane, excessive risks in underwriting Federal Housing Administration mortgages, riots, and civil disorders, the Agency for International Development commodity import program, and procurement of railway bridges for South Vietnam under the counter-insurgency program. The Subcommittee’s investigations also led to passage of major legislation against organized crime, most notably the Racketeer Influenced and Corrupt Organizations Act ("RICO act"), which is a section of the Organized Crime Control Act passed in 1970.
In 1973, Senator Henry M. Jackson, a Democrat from Washington, replaced McClellan as the Subcommittee’s chairman and Senator Charles H. Percy, an Illinois Republican, became the Ranking Minority Member. During Senator Jackson’s chairmanship, the Subcommittee conducted landmark hearings into energy shortages and the operation of the petroleum industry.
The regular reversals of political fortunes in the Senate of the 1980s and 1990s saw Senator Sam Nunn trade chairmanship three times with Delaware Republican William V. Roth Jr.. Nunn served from 1979 to 1980 and again from 1987 to 1995, while Roth served from 1981 to 1986, and again from 1995 to 1996. Senator Roth led a wide range of investigations into commodity investment fraud, off-shore banking schemes, money laundering, and child pornography. Senator Nunn inquired into federal drug policy, the global spread of chemical and biological weapons, abuses in Federal Student Aid programs, computer security, aviation safety, and health care fraud.
In January 1997 Republican Senator Susan Collins of Maine became the first woman to chair the Permanent Subcommittee on Investigations. Her Chairmanship was also notable in that she held the Senate seat of former Maine Senator Margaret Chase Smith, an opponent of Senator McCarthy. Senator John Glenn of Ohio became Ranking Member. Upon Senator Glenn’s retirement from the Senate, Senator Carl Levin became Ranking Member in 1999. In June 2001, when the Democrats resumed control of the Senate, Senator Levin assumed the chairmanship of the Subcommittee until January 2003 when Senator Norm Coleman assumed the Chairmanship. When the Democrats took control of the Senate in January 2007, the chairmanship reverted to Senator Levin.
In December 2004, Coleman called for Secretary-General of the United Nations Kofi Annan to resign because of the "UN's utter failure to detect or stop Saddam's abuses" in the Oil-for-Food Programme and because of fraud allegations against Kojo Annan, his son, relating to the same program. In May 2005 the subcommittee held Oil-for-Food Program Hearings to investigate abuses of the Oil-for-Food program, including oil smuggling, illegal kickbacks and use of surcharges, and Saddam Hussein's use of oil vouchers for the purpose of buying influence abroad. These hearings covered certain corporations, including Bayoil Inc., and Russian politician Vladimir Zhirinovsky. The hearings received significant media attention for the combative appearance of British politician George Galloway of the Respect Party, in which he forcefully rejected the allegations.
On April 13, 2011 the Committee released its report on Wall Street and the Financial Crisis: Anatomy of a Financial Collapse. The 635-page bipartisan report was issued under the chairmanship of Carl Levin and Tom Coburn and also thus referred as the Levin-Coburn Report. It represents an in-depth investigation as well as a permanent record of the financial crisis of 2007–08 and took over two years of research and investigations to compile. It found “that the crisis was not a natural disaster, but the result of high risk, complex financial products; undisclosed conflicts of interest; and the failure of regulators, the credit rating agencies, and the market itself to rein in the excesses of Wall Street.” 
We marched 2 days. The first night we got some hay and we slept in the hay cuddling together to keep warm. The second night we slept in pigpens, about 6 inches space between the logs. That night I froze my feet. Starting out again the next morning after bypassing the convoy I picked up two rubber boots, what we call snow packs. They was both for the left foot. I put those on. After starting out the second morning, I didn't have time to massage my feet to get them thawed out. I got marching the next 16 days after that. During that march all the meat had worn off my feet, all the skin had dropped off, nothing but the bones showing. After arriving in Kanggye they put us up there in mud huts, Korean mud huts. We stayed there-all sick and wounded most of us was-stayed there in -the first part of January 1951. Then the Chinese come around in the night about 12 o'clock and told us those who was sick and wounded they was going to move us out to the hospital, which we knew better. There could have been such a thing but we didn't think so. --Sgt. Wendell Treffery, RA-115660.