Sorry to be the bearer of bad news but late blight is in Madison County. Please be on the look out for it. Keep your tomato plants well pruned and up off the ground for circulation. Even though I just pruned mine 2 weeks ago they had already become overgrown with side shoots. I spent this morning trying to get them back in shape by pruning and staking.
There are some chemicals you can use. I will be applying vermicompost tea twice a week. Let's all hope it doesn't become too bad. Below are a couple of links. There is also a blog post from last year with more information about late blight.