Baptist patriotism becomes especially evident on the Sunday preceding July 4.
The good. At our church yesterday we did a responsive reading (something I think Baptists do all too rarely, even though our hymnals usually contain a good-sized collection of them). I thought it was great. The reading was made up of Bible passages about loving God, loving one another, honoring the king, and some other stuff that I'm sorry to say has since slipped my mind.
The bad. The Sunday before July 4, 2001, my family visited a Baptist church somewhere in or near Friendswood, Texas. The celebration of America was very enthusiastic. At one point the projector showed an image of Jesus' face superimposed over the American flag. My brother's sarcastic remark: Today in church I learned that Jesus is an American.
And, of course, in between there are any number of other traditions like singing various patriotic songs (usually, but not always, religious ones), and recognizing church members who served in the armed forces.
I don't actually know what, if anything, the churches with established liturgies do differently during Independence week. Nor am I entirely sure what Christians should be doing in church during Independence week. There's no need to let patriotism get out of control, but patriotism itself is a good thing; the chief danger, of course, is that we will let it distract us from the Gospel.