According to Chas West Wilson on page 256 of his Westmoreland Glass, Indentification and Value Guide items in the #1776 Line were Keystone W marked and have ground and polished bases. The blue color was first advertised in late 1924 and was made for only 5 years. The line was discontinued in 1940.
The Laurel Green color was issued after 1960 - the various colonial pieces reissued during the 1960's were also marked, but do not have the ground and polished bases.
