KNIGHTS OF LABOR (OMN) cen by Central Glass Company (Wheeling-WV, Company Operated: 1867-1891), c1870s Introduced
NOTE: Mordock's Pattern Glass Mugs states that the "labor union was formed in 1869 by Uriah Stevens in Philadelphia". The stein was only produced in clear. The catalog cut is from Revi, Albert Christian "American Pressed Glass and Figure Bottles" page 113 and is referenced in Mordock/Adams [about an ale glass].
image 1 of 2

Shape: Cups & Mugs
Contributor: Michele Richard

Shape: Stemware
Contributor: Gene Serbus ale glass

Shape: Catalogue/Ads
Contributor: Gene Serbus cut from Revi, see NOTE

Shape: Cups & Mugs
Contributor: Heidi Crupe 4.75T