Of course they had a flag. Every nation has a flag. Just because they designed it doesn't mean they placed the import on it that you are doing. It's sort of one of the things you do. Write a constitution, develop the government, and oh yes, design a flag to put on your ships!! Sort of prevented getting shot and boarded wouldn't you think?
And yet you take this as some sign that the Framers put the same level of importance to a symbol as you do? Where's the pledge? Oh, I forgot that was written by a Socialist over a hundred years later.