This is a vintage Borden's Baby Brand Condensed Milk jar produced by Borden's Condensed Milk Company of New York.  The octagonal bottle is embossed on the bottom, "Bordens Condensed Milk Co"  encircling the number 2 and "Baby".  The company utilized the name between 1899 and 1919 after a lawsuit regarding naming rights.  Borden began producing condensed milk during the Civil War when they discovered it could be stored for long periods.  After the war ended, Borden began marketing the product as an infant formula that would not spoil.  My father, an avid bottle digger, discovered the antique bottle in the ruins of an old homestead in Virginia more than 40 years ago.  The vintage milk bottle is in great shape, free from breaks or cracks.  There is some light discoloration from long term exposure.  (See photos).  The old dairy jar measures about 4.25" x 2.75".  Note: the paper image was found on line and is for informational purposes and not included.