By Chris Cillizza

CNN Editor-at-large

(CNN) -- Louisiana's Steve Scalise is the 9th member of Congress to be shot while in office and one of two dozen to be targeted by attackers since 1789, according to a 2011 Congressional Research Service report.

Scalise, the third-ranking Republican in the House, was shot in the hip by a man wielding a rifle at an early-morning practice for the GOP baseball team in advance of the scheduled Congressional Baseball Game tomorrow. He was one of five people injured -- including two members of the US Capitol Police force -- in the shooting.

The Louisiana congressman was, according to a statement released by his office, undergoing surgery Wednesday morning but in stable condition.

He is the first member of Congress to be shot since January 2011 when then Arizona Rep. Gabrielle Giffords, a Democrat, was shot in the head at a congressional event in Tucson. "My heart is with my former colleagues, their families & staff, and the US Capitol Police - public servants and heroes today and every day," Giffords tweeted in the immediate aftermath of the shooting.

Six people were killed in the Arizona shooting that targeted Giffords. She returned to Congress in August 2011, but resigned from the chamber in January 2012.

Other attacks were not included in the report, such as the 1998 shooting inside the Capitol when a gunman stormed into the building and shot and killed two Capitol Hill police officers. That gunman had a history of mental illness.

Prior to the attack on Giffords, it had been three decades since a member of Congress had been attacked. In November 1979, a woman with a knife got into Ted Kennedy's Senate office. She was stopped by the US Secret Service prior to reaching Kennedy; a Secret Service officer was "slightly wounded" according to CRS.

Almost a year to the day prior, California Rep. Leo Ryan was shot and killed at an airstrip in Guyana after he and two dozen others traveled to investigate the Jonestown cult headed by Jim Jones, which was based there. Ryan, along with four others -- including three journalists -- were murdered. Jackie Speier, who now holds Ryan's seat, was on that trip as a staffer to the Congressman. She was shot five times but lived. (Jones as well as 908 of his followers committed mass suicide by poisoning on the same day Ryan was killed.)

A decade earlier, New York Sen. Robert Kennedy, then a leading candidate for the Democratic presidential nomination, was assassinated in Los Angeles following his victory in the June California primary.

The incident involving the most members of Congress happened on March 1, 1954 when a group of Puerto Rican nationalists entered the House press gallery and opened fired. Reps. Clifford Davis (Tennessee), Alvin Bentley (Michigan), Ben Jensen (Iowa), George Hyde Fallon (Maryland) and Kenneth Roberts (Alabama) were injured -- although all five recovered. At issue was the ongoing US control of Puerto Rico.

Prior to that, the most high profile attacks on members of Congress both deal with Louisiana Sen. Huey Long. In February 1935, a bomb was sent to Long's Senate office in Washington. It was opened by his secretary but had been damaged in the mail and did not explode. Seven months later, Long was shot in the Louisiana state capitol building. He died two days later. (The identity of his shooter was long a mystery.)