Each of the known Erwin Strasser Washington FDCs is a registered cover with a Hayes stamp and a 1-cent Pilgrim Tercentenary stamp (Scott 548) to make up the required postage. They are similar to his Fremont FDCs. Even though there are only three known Strasser Washington covers, an examination of their registration numbers (below) indicates that a fourth Washington FDC was made by Strasser. He also made four Fremont FDCs.
The Strasser covers and the Ward cover all received special handling from the Philatelic Stamp Agency. Each had applied to it an Agency handstamp on the front of the cover and a wax seal of the Division of Stamps on the back of the cover. This was the first time that the Agency handstamp was used on FDCs. Even though there is evidence of a wax seal on the above cover, it was removed or fell off the cover.