According to Northeast D.C. Gets A New Mural Honoring The Workers Who Built The Lincoln Memorial Statue, artist "Baker named his installation “28 Blocks” after the number of stone blocks used to make the famous sculpture in the Lincoln Memorial."
Spanning four stories and a city block and composed of 130 polyurethane-coated panels, the mural shows the quarrrying of Georgia marble by the sons and grandsons of freed slaves, and the carving of the of the Lincoln Memorial statue by a family of Italian immigrant sculpters.
Street parking is available, and as usual with this urban series, expect coords to be approximate; once you see the murals you'll need to rely on your geosense more than your GPS.
Please remember to practice stealth, replace just as found, and don't forget your favorite writing utensil -- enjoy!
Hint is a bit of a giveaway, so avoid if you prefer a challenge.
Don't leave without walking bit south down the MBT to see another set of murals, which should be visible from GZ looking toward the train tracks, you won't be sorry you did!
** Congrats to ender's wolf pack for the FTF! **