Question: Speedway LLC is a wholly owned subsidiary of what corporation that was named best employer of the United States by Forbes in 2016?
Sentence (from "Johnsonburg, Kane, Warren and Irvine Railroad"): The JKWI was the designated operator of the Irvine, Warren, Kane & Johnsonburg Railroad, that was a partnership of Brock Railroad (a wholly owned subsidiary of Warren Car Company), Irvine Railroad (a wholly owned subsidiary of National Forge Company) and Struthers Wells Inter-American Corporation (a subsidiary of Struthers Wells), all three being Pennsylvania corporations, and had acquired from Conrail the following railroad line segments: MP 58.52 to MP 66.7 (Irvine to Warren) and MP 92.5 to MP 111.0 (Kane to Johnsonburg).
Relevant evidence: No