By the end of 1936, all the boxes with this label design were switched to the blue color.
The 'Trade Mark' game is the ultimate Parker Brothers Monopoly game for a collector.
Canadian Monopoly games were introduced in 1936 and closely resembled the U. (Thanks, JP) The game boxes pictured below show different label designs and kind of a chronology of manufacture.
I'm always adding new box varieties so check back once in a while for updates.
Please feel free to email me with corrections, questions, or comments.
Also, check out the online Vintage Monopoly Game Collectors group This style box was a Darrow design and Parker Brothers just continued production using his design.
Dating early Monopoly games is done by the patent numbers and cities listed on the labels.
The new patent was added to the labels and games produced from 1936 - 1941 included both patents printed on the labels.
Parker Brothers applied for their own patent and the next group of their games stated PATENT PENDING or PATENT APPLIED FOR. This statement was used for a while in 1935, but they discovered that there were other games very much like Monopoly already with patents.
To protect their investment in Darrow's Monoply game, they decided to purchase the 1924 patent to the Landlords game and added that patent to their Monopoly games. In the meantime, PB applied for their own patent on Monopoly.
Once Parker Brothers figured out Monopoly was taking off, they decided to offer a variety of different game options.
One of the first things changed was the color of the box from black to blue.