Michael Grimm (R-NY) pleaded guilty of felony tax evasion. This was the fourth count in a 20-count indictment brought against him for improper use of campaign funds. The guilty plea had a maximum sentence of three years; he was sentenced to three months in prison. (2015)
Trey Radel (R-FL) was convicted of possession of cocaine in November 2013. As a first-time offender, he was sentenced to one year probation and fined $250. Radel announced he would take a leave of absence, but did not resign. Later, under pressure from a number of Republican leaders, he announced through a spokesperson that he would resign. (2013)
Rick Renzi (R-AZ) was found guilty on 17 of 32 counts against him June 12, 2013, including wire fraud, conspiracy, extortion, racketeering, money laundering and making false statements to insurance regulators. (2013)
Jesse Jackson, Jr. (D-IL) pleaded guilty February 20, 2013, to one count of wire and mail fraud in connection with his misuse of $750,000 in campaign funds. Jackson was sentenced to two and one-half years’ imprisonment. (2013)
Laura Richardson (D-CA) was found guilty on seven counts of violating US House rules by improperly using her staff to campaign for her, destroying the evidence and tampering with witness testimony. The House Ethics Committee ordered Richardson to pay a fine of $10,000. (2012)
Scott Bloch (R) United States Special Counsel. pleaded guilty to criminal contempt of Congress for “willfully and unlawfully withholding pertinent information from a House Committee investigating his decision to have several government computers wiped ….” On June 24, 2013, U. S. District Judge Robert L. Wilkins sentenced Bloch to one day in jail and two years’ probation, and also ordered him to pay a $5000 fine and perform 200 hours of community service.(2010) 
Lewis Libby (R) Chief of Staff to Vice President Dick Cheney (R). ‘Scooter’ was convicted of perjury and obstruction of justice in the Plame Affair on March 6, 2007 and was sentenced to 30 months in prison and fined $250,000. His sentence was commuted by George W. Bush (R) on July 1, 2007. (2007)
William J. Jefferson (D-LA) was charged in August 2005 after the FBI seized $90,000 in cash from his home freezer. He was re-elected to the House in 2006, but lost in 2008. He was convicted November 13, 2009, of 11 counts of bribery and sentenced to 13 years in prison. (2009) Jefferson’s Chief of Staff Brett Pfeffer, was sentenced to 84 months for bribery. (2006) 
Jack Abramoff CNMI scandal involves the efforts of Abramoff to influence Congressional action concerning U.S. immigration and minimum wage laws. See Executive branch convictions. Congressmen convicted in the Abramoff scandal include:
Bob Ney (R-OH) pleaded guilty to conspiracy and making false statements as a result of his receiving trips from Abramoff in exchange for legislative favors. Ney received 30 months in prison. (2007)
Duke Cunningham (R-CA) pleaded guilty November 28, 2005, to charges of conspiracy to commit bribery, mail fraud, wire fraud and tax evasion in what came to be called the Cunningham scandal and was sentenced to over eight years in prison. (2005)
Bill Janklow (R-SD) was convicted of second-degree manslaughter for running a stop sign and killing a motorcyclist. Resigned from the House and given 100 days in the county jail and three years probation. (2003)
Jim Traficant (D-OH) was found guilty on ten felony counts of financial corruption, sentenced to eight years in prison and expelled from the House of Representatives. (2002) 
Darleen A. Druyun (D), Principal Deputy United States Under Secretary of the Air Force. She pleaded guilty to inflating the price of contracts to favor her future employer, Boeing. In October 2004, she was sentenced to nine months in jail for corruption, fined $5,000, given three years of supervised release and 150 hours of community service.(2005). CBS News called it “the biggest Pentagon scandal in 20 years” and said that she pleaded guilty to a felony.
Mel Reynolds (D-IL) was convicted on 12 counts of sexual assault, obstruction of justice and solicitation of child pornography. (1997) He was later convicted of 12 counts of bank fraud. (1999) Reynolds served his entire sentence stemming from the first conviction and served 42 months in prison for the bank fraud conviction at which point his sentence was commuted by President Bill Clinton. As a result, Reynolds was released from prison and served his remaining time in a halfway house.
Bob Packwood (R-OR), 19 women accused him of sexual misconduct. He fought the allegations, but eventually, the US Senate Ethics Committee found him guilty of a “pattern of abuse of his position of power and authority” and recommended that he be expelled from the Senate. He resigned on Sept. 7, 1995.
Wes Cooley (R-OR), was convicted of having lied on the 1994 voter information pamphlet about his service in the Army. He was fined and sentenced to two years probation (1997) After leaving office, Cooley was convicted of income tax fraud connected to an investment scheme. He was sentenced to one year in prison and to pay restitution of $3.5 million to investors and $138,000 to the IRS.
Austin Murphy (D-PA) was convicted of one count of voter fraud for filling out absentee ballots for members of a nursing home. (1999) 
House banking scandal The House of Representatives Bank found that 450 members had overdrawn their checking accounts, but not been penalized. Six were convicted of charges, most only tangentially related to the House Bank itself. Twenty two more of the most prolific over-drafters were singled out by the House Ethics Committee. (1992)
Nicholas Mavroules (D-Massachusetts) was convicted of extortion, accepting illegal gifts and failing to report them on congressional disclosure and income tax forms. Mavroules pleaded guilty to fifteen counts in April 1993 and was sentenced to a fifteen-month prison term. (1993) 
Albert Bustamante (D-Texas) was convicted of accepting bribes and sentenced to three and one-half years in prison. (1993) 
David Durenberger Senator (R-Minnesota) denounced by Senate for unethical financial transactions and then disbarred (1990). He pleaded guilty to misuse of public funds and given one year probation (1995) 
Jay Kim (R-CA) accepted $250,000 in illegal 1992 campaign contributions and was sentenced to two months house arrest. (1992)
Iran-Contra Affair (1985–1986); A secret sale of arms to Iran, to secure the release of hostages and allow U.S. intelligence agencies to fund the Nicaraguan Contras, in violation of the Boland Amendment.
J. Herbert Burke (R-FL) pleaded guilty to disorderly intoxication, resisting arrest, and nolo contendere to an additional charge of witness tampering. He was sentenced to three months plus fines.(1978)
Fred Richmond (D-New York) – Convicted of tax fraud and possession of marijuana. Served 9 months in prison. Charges of soliciting sex from a 16-year-old boy were dropped after he submitted to counseling. (1978) 
Charles Diggs (D-Michigan), convicted on 29 charges of mail fraud and filing false payroll forms which formed a kickback scheme with his staff. Sentenced to 3 years (1978) 
Michael Myers (D-Pennsylvania) Received suspended six-month jail term after pleading no contest to disorderly conduct charged stemming from an incident at a Virginia bar in which he allegedly attacked a hotel security guard and a cashier.
Frank M. Clark (D-Pennsylvania) pleaded guilty to mail fraud and tax evasion on June 12, 1979 and sentenced to two years in prison.
Richard Tonry (D-Louisiana) pleaded guilty to receiving illegal campaign contributions.
Earl Butz (R) Secretary of Agriculture. He was charged with failing to report more than $148,000 in 1978. Butz pleaded guilty to the tax evasion charge and was sentenced to 30 days in jail and five years of probation and was ordered to make restitution. He served 25 days behind bars before his release.
James F. Hastings (R-New York), convicted of kickbacks and mail fraud, he also took money from his employees for personal use. Served 14 months at Allenwood penitentiary. (1976) 
John V. Dowdy (D-Texas), Allegedly tried to stop a federal investigation of a construction firm. He served 6 months in prison for perjury. (1973) 
Bertram Podell (D-New York), pleaded guilty to conspiracy and conflict of interest. He was fined $5,000 and served four months in prison. (1974)
Frank Brasco (D-New York) Sentenced to three months in jail and fined $10,000 for conspiracy to accept bribes from a reputed Mafia figure who sought truck leasing contracts from the Post Office and loans to buy trucks.
Watergate (1972–1973) Republican ‘bugging’ of the Democratic Party National Headquarters at the Watergate Hotel led to a burglary which was discovered. The cover up of the affair by President Richard Nixon (R) and his staff resulted in 69 government officials being charged and 48 pleading guilty, including 7 for actual burglary. Eventually, Nixon resigned his position.
Maurice Stans (R) Secretary of Commerce, pleaded guilty to three counts of violating the reporting sections of the Federal Election Campaign Act and two counts of accepting illegal campaign contributions and was fined $5,000.(1975)
J. Irving Whalley (R-Pennsylvania) Received suspended three-year sentence and fined $11,000 in 1973 for using mails to deposit staff salary kickbacks and threatening an employee to prevent her from giving information to the FBI.
Martin B. McKneally (R-New York) Placed on one-year probation and fined $5,000 in 1971 for failing to file income tax return. He had not paid taxes for many years prior.
James Fred Hastings (R-NY) Resigned on January 20, 1976 after being convicted of kickbacks and mail fraud. He served 14 months at Allenwood penitentiary (1976).
1963–1969 (Lyndon B. Johnson (D) presidency)
Ted Kennedy (D-Massachusetts) drove his car into the channel between Chappaquiddick Island and Martha’s Vineyard, killing passenger Mary Jo Kopechne. Kennedy pleaded guilty to leaving the scene of an accident and received a suspended sentence of two months  (1969)
Daniel Brewster (D-Maryland) pleaded no contest to accepting ” an unlawful gratuity without corrupt intent “.
Thomas F. Johnson (D-Maryland) was convicted of conspiracy and conflict of interest regarding the receipt of illegal gratuities.
Frank Boykin (D-Alabama) Was placed on probation and fined $40,000 following conviction in a case involving a conflict of interest and conspiracy to defraud the government. He was pardoned by President Lyndon Johnson in 1965.
Thomas J. Lane (D-Massachusetts) convicted for evading taxes on his congressional income. Served 4 months in prison, but was re-elected three more times. before his 1962 defeat due to re-districting. (1956) 
Ernest K. Bramblett (R-California) Received a suspended sentence and a $5,000 fine in 1955 for making false statements in connection with payroll padding and kickbacks from congressional employees.
John W. Langley (R-KY) Resigned from the US Congress in January 1926, after losing an appeal to set aside his conviction of violating the Volstead Act (Prohibition). He’d also been caught trying to bribe a Prohibition officer. He was sentenced to two years after which, his wife ran for Congress in his place and won two full terms.