Since all the sources I can find on the web directly contradict your statement about 80 years of voting representation - at least in Congress. Source, please.

As for the other inaccuracies in your post:
1. The 23rd amendment, granting DC 3 votes in presidential elections, passed in 1961 under Kennedy. I don't remember a war in 1961...the 23rd was proposed by Congress and ratified by the requisite number of states. Still not a constitutional convention.
2. there was an attempt in 1978 to get an amendment passed to confer statehood on DC. It failed miserably - only 16 states out of 38 signed on. STILL not a constitutional convention.
3. In 1982, DC residents approved a so-called constitutional convention and drafted a state constitution, attempting to repeat the steps taken by other states when they were still territories. However, Congress never approved it, and so it has no force.
4. You're partially correct on federal taxes. Residents of the various territories pay taxes under the same tax structure as the U.S., using the same forms we do. However, they are considered to be a separate taxing jurisdiction so all tax revenues go to the local government.

1.5 out of 5. You're not doing so good.

Assuming you weren't born in DC and have stayed there all your life, did you not know when you moved to DC that you wouldn't have complete representation? You do get all the other benefits of U.S. citizenship, so trying to give the ipression that DC is no better than a colony is specious. If you really feel that you're being shortchanged, your only current option is to relocate. It will most likely take a constitutional amendment for DC to be granted statehood. Based on the results from the last attempt in 1978, I don't like your chances.

Of course, there is another option - let Maryland take back the land it originally gave up. That way, you would be a Marylander. Yippee!

In the meantime, on the original topic:
The Supreme Court in Heller vs. DC held, unanimously, that the 2nd amendment is an individual right. The point of disagreement was on what level of regulation abridges that right. In McDonald vs. Chicago, the 2nd was incorporated under the 14th amendment, meaning that it applies to all states. (The Heller decision applied it specifically to DC)

Anything else?