But all of that is Robinson redux; Opal City didn't exist until James Robinson created it out of wholecloth for the Jack Knight version of Starman in 1994 (one of the principle new offerings stemming from the "Zero Hour" reboot).
In the Golden Age, artist-creator Jack Burnley set Starman in Gotham. Yup. Gotham. Not "Gotham City" where Batman lived; Ted Knight (Starman) lived in just Gotham, another paper-thin copy of New York City. Interestingly, a reference to NYC in one of the early stories (Adventure No. 63) makes the point that the Gotham where Ted lives in NOT New York City.
Later on, however, Starman was "retconned" (as we call it nowadays) to live in Federal City, whose name alone makes it clear is an analog for Washington, D.C. As we learned in a 1970's retcon, Ted Knight had political connections in Federal City; his uncle was a U.S. Senator, whose daughter (inspired by her cousin's career) became the tantalizing Phantom Lady. To paraphrase Plastic Man, "Yes, we all love Phantom Lady."
Robinson and others respected the Federal City connection by building into Ted Knight's back story a period where he left Opal City to heroize in Washington, D.C.
But I call for the elimination of Washington, D.C., from the DCU.
I myself live in D.C., for 20 years now. [Note: People who live in Washington do NOT call it Washington. In fact, they never use the word "Washington"; even the Washington Monument is just "The Monument". If you meet someone who says he lives in "Washington", he doesn't; he lives in the D.C. suburbs.] But I do not want a D.C. in the DCU. I want Federal City (F.C. !) instead.
- I want to have a superhero running around in the nation's capitol (something that I know wouldn't go well in the real D.C.)
- The District of Columbia is, frankly, a stupid name; Federal City is much cooler.
- I like the principal (American) cities of reference in the DCU to be fictionopolises, so that the DCU feels like its built around its main characters, rather than feeling as if editors tried to awkwardly squeeze a legion of superpowered people into our world.
- If we're going to have fictional presidents (particulary ones who become supervillains upon retirement, which seems to be the post-presidential career of choice lately), it's more comfortable if they are in fictional context (F.C. rather than D.C.).
A retcon of D.C. as F.C. (heck, "Washington, F.C." would work fine for me) wouldn't affect DCU history and would free up its future a bit. F.C. could be home to Wonder Woman (gods know she needs one) or maybe even (unbelievable!) an actual black hero native to the city! My vote for that character would be the obscure Manager Lad, an underused creation of Jack Kirby and Steve Ditko...