Young people are celebrating Summerween and American Eagle is ready for fall   While Summerween has been an official holiday for those in fictitious Gravity Falls, Oregon for years, young people have become more acquainted with the holiday on social media this month. Over on Instagram, the hashtag #Summerween has over 76K posts and on TikTok it has over 31K posts. Videos show the best ways to celebrate, encouraging viewers to throw pool parties riddled with pumpkins, orange decor, and fall-themed treats. One viral post on Instagram from @leladymoon shows a “Summerween Checklist” that includes, “read horror books, make a spooky...