Cut brisket to fit crock-pot, if necessary. Trim off fat. Combine chili powder, garlic powder, celery seed [or powder], and pepper in large bowl or pan, rub over meat. Place in crock-pot.
In large bowl combine the rest of the ingredients to make a sauce, pour over meat.
Cover and cook on low setting for 8-10 hours or on high setting for 4-5 hours. Remove meat and slice in thin pieces across the grain. Skim fat off, and use the juices on meat or put meat back into it after slicing.