Place tea bags, sugar and mint leaves in large measure; pour in boiling water, stirring to dissolve sugar.
Let steep for 6 minutes or until desired strength; remove tea bags.
Refrigerate for 8 hours.
Strain into serving pitcher.
(Tea can be prepared to this point and refrigerated for up to 3 days.) Add lemon slices, lemon juice and ice.
Garnish with mint sprigs.