The defunct website Emporis said the building is from 1965. The Shawnee County government's real estate search website says the building is from 1980. Online, I have been unable to find any other sources that would corroborate or refute either date. It kind of looks more like 1965, but 1980 is not implausible, right?
The office tower was built by the Security Benefit Life Insurance Company as an addition to its headquarters at the left. It was sold to the State of Kansas in 1999, per many news articles in the Topeka Capital-Journal, which I viewed online in a university library database. As best as I can tell, none of the articles say anything about when the tower was built.
I guess we'll never find out when it was built! The building will probably be demolished before long, so maybe it doesn't matter much.
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In downtown Topeka, Kansas, on March 28th, 2022, the Dwight D. Eisenhower State Office Building (dedicated as such in 2005) at the southwest corner of SW 7th Street and SW Van Buren Street, as viewed from the southeast corner of SW 8th Avenue and SW Harrison Street.
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Getty Thesaurus of Geographic Names terms:
• Shawnee (county) (2000748)
• Topeka (7013945)
Art & Architecture Thesaurus terms:
• brown (color) (300127490)
• corporate headquarters (built works) (300132690)
• insurance (300055719)
• Modern Movement (300121793)
• office towers (300007046)
• panels (surface elements) (300069079)
• parking lots (300007826)
• public buildings (governmental buildings) (300008059)
• repurposing (300417716)
• state government (300055504)
Wikidata items:
• 28 March 2022 (Q69306380)
• life insurance (Q626608)
• March 28 (Q2458)
• March 2022 (Q61312974)
• Treaty with the Kansa, 1825 (Q111541683)
• Treaty with the Shawnee, 1854 (Q111540627)