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Unfortunately, Washington DC postal history seems not to be of much interest.
And yet ... official mail cards and envelopes from Washington, DC are a fruitful place to search for experimental and short-run machine cancels as the Post Office Department often ran a stack of this uniform-sized official mail as live test material.
Your card has a Barr-Fyke machine cancel, one of the less common brands, and which exists in nearly a dozen variants from DC over a span of a few years as part of a contract, thus each machine arrangement is very short-lived.