MacArthur Foundation — Founder (text): John D. MacArthur

NoteThe source directly confirms that John D. MacArthur is one of the founders of the MacArthur Foundation. The Wikidata page explicitly lists 'John D. MacArthur' under the 'founded by' property. The claim asks specifically about 'MacArthur Foundation's Founder (text) = John D. MacArthur', and the source text shows this exact text value in the 'founded by' field. Note that Catherine T. MacArthur is also listed as a co-founder, making this a partial listing rather than exclusive, but the claim is not contradicted—it accurately identifies one of the two founders.