In 1903 parties (George Sternberg and George Kober) involved with the Washington Sanitary Improvement Company owned the following lots on Sq. 615 (bounded by North Cap, Q St, 1st St and P St NW): 65-66, 134-140, 170-179, 195-207, and 236-265.
Fast forward to the 1933-1934 General Assessment, and it looks like the Washington Loan and Trust Company was holding or acting as a trustee for the WSIC.
There was a document that the WSIC owned the following lots in 1950. Lots 0134, 0135, 0136, 0137, 0138, 0139, 0140, 0170, 0171, 0172, 0173, 0174, 0175, 0176, 0177, 0178, 0179, 0195, 0196, 0197, 0198, 0199, 0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207, 0236, 0237, 0238, 0239, 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247, 0248, 0249, 0250, 0251, 0252, 0253, 0254, 0255, and 0256. So basically the same lots, minus lots 65-66.
Next, I need to do a wide search to see if WSIC owned anything else in Truxton Circle, besides Squares 552 and 615. I don’t think so, but I need to check.