Prior to his election to the Congress, Slattery served in the Kansas House of Representatives, as a reserve Army officer and founded a successful[citation needed] real estate company.

He was a central player on many key issues, including environmental protection, health care, telecommunications, and budget cutting efforts.

He worked to limit production of the B-2 bomber, and was the chief sponsor of the successful amendment to terminate spending on the Superconducting Super Collider in 1993.

[7] The SSC would have been about three times as powerful as CERN's Large Hadron Collider, most notable for discovering a particle consistent with a Higgs boson.

Finney served one term as governor, and Slattery decided to run for the open governorship in 1994, stepping down from Congress.

[13] Jim Slattery has been practicing law since 1975 and has advised domestic and international clients who have matters pending before the U.S. Congress, federal agencies, and regulatory bodies.

He has special experience in public policy matters related to health care, railroads, International trade, Ukraine, and Iran.

[14] He has also done various consulting and pro bono work, including successfully advocating for the release of a Princeton University student who had been imprisoned in Iran.

[18][19][20] In 2019, Slattery assisted with the release of Xiyue Wang, a Princeton University student who was imprisoned in Iran from 2016 to 2019 after being accused of espionage.