Boil elbow macaroni according to package directions until al dente. Drain and rinse under cold water.
Chop the celery, onion, and red bell pepper. Dice the hard-boiled eggs.
In a medium bowl, whisk together Miracle Whip, mustard, sugar, vinegar, celery seed, salt, and pepper. Adjust seasoning to taste.
In a large bowl, mix the pasta with eggs, vegetables, and relish. Pour the dressing over the top and stir gently until evenly coated.
Cover and refrigerate for at least 1 hour before serving to allow flavors to meld.
