Melt oil in bottom of large cooking pot. Add onion, green pepper, celery, and garlic and cook until partially tender, stirring occasionally. Add beef and fry uncovered until browned. Add tomatoes and chili powder, which has been mixed with 2 tablespoons cold water. Add salt and sugar. Cover, bring to boil, then simmer slowly for about 1 hour or until thickened. Add beans and heat well. Serve with bowls of crackers, hard rolls or cornbread and a green salad. Recipe can be easily doubled and extra servings frozen.