According to the Wantagh Preservation Society, the business was listed in a 1939 Wantagh Long Island advertising booklet as:
Willow Dairy, George Hendrickson, Prop. Grade A Milk and Cream. Seaman’s Neck Road. Phone 1048.
This is confirmed in the 1940 census records where George Hendrickson was listed as the owner of a dairy farm on Seaman’s Neck Road. Living with him were his son Lloyd, who was listed as a dairy farm bottler, four dairy farm hands and a cook. Based on this, I assume that the business was small and local to the Wantagh/ Seaford area of Long Island.
Prior to that, in the 1920’s and early 1930’s, he was located in Oceanside Long Island. The 1920 census listed him as a milk inspector and in the 1926-1927 Rockville Centre City Directory, including Oceanside and East Rockaway, he was listed as the proprietor of a dairy at 88 Anchor Avenue.
He was still listed as a the proprietor of a dairy farm in Oceanside in the 1930 census records but was not listed in the 1937 edition of the Rockville Centre Directory. So sometime between 1930 and 1937 he moved to Wantagh/Seaford and either took over or started the Willow Dairy.
In 1941, Willow Dairy participated in a tour organized by the Long Island Dairy Herd Improvement Association and the Farm Bureau of Nassau and Suffolk Counties. An October 12, 1941 article in the Brooklyn Daily Eagle explained:
The public will be given an opportunity to learn by first-hand observation the intricacies of running a dairy farm through a dairy tour to be held in Nassau and Suffolk on Oct. 28…the inspection trip also will give dairymen a chance to study the operation of other farms.
Starting at the farm of George Hendrickson, Wantagh, the tour will inspect John Randall’s farm, Mount Sinai, where lunch also will be served, proceed to the Pierson farm at East Moriches and end at the Gould Dairy in East Hampton.
It’s not clear when the business ended but the bottle I found is embossed “duraglas” with a 1949 date code embossed on the base. So they were at least in business from the mid 1930’s to the late 1940’s. It was probably gone by 1958 when the original Seaman’s Neck Road was acquired to facilitate construction of the Seaford Oyster Bay Expressway.
The bottle I found is a machine made quart with the 1949 date code.