Question: The McDonald Farm supplied stone for a monument that honors which historical figure?
Sentence (from "Washington Monument"): Located almost due east of the Reflecting Pool and the Lincoln Memorial, the monument, made of marble, granite, and bluestone gneiss, is both the world's tallest stone structure and the world's tallest obelisk, standing 554 ft tall according to the National Geodetic Survey (measured 2013–14) or 555 ft tall according to the National Park Service (measured 1884).
Relevant evidence: No