The Senate Hart Office Building is the third U.S. Senate building, designed by in the 1970's. Named for Philip A. Hart, long-time senator from Michigan.
Following a recomendation from George M. White (then the serving Architect of the Capitol) the plan submitted by the architectural firm of John Carl Warnecke & Associates; it was approved by the Senate Committee on Public Works on August 8, 1974. Construction proceeded, and the building was first occupied in November of 1982.
In the fall of 2001, several suites of this building became contaminated by the release on anthrax powder from an envelope mailed to Senator Tom Daschle. The building was closed. The cleanup was finished in December, 2001 [1].