For more than a century, Hallmark cemented a legacy in greeting cards, occasions ranging from graduation to Valentine's Day. Hallmark was the go-to for a sentimental, heartfelt message.. The company applied this strategy to its cable channel, which was first established in 2001. It wasn't until the 2010s that the Hallmark Channel leaned into TV films centered around the holidays, especially Christmas, often following a comforting formula and promising a happy ending.