McDonald's is the world's largest restaurant chain founded in 1940 in California. It now has over 37,000 outlets globally serving 69 million customers daily. McDonald's uses extensive advertising including billboards, sports sponsorships, and television commercials focusing on emotions and family. It has had celebrity partnerships promoting meals like the Travis Scott and BTS meals. McDonald's also sponsors NASCAR racing and has faced challenges like declining sales in the late 1990s that it overcame through new marketing strategies and improved management.