What contribution did New York ad writer Robert May make to the Santa Claus legend in 1939?

In 1939, New York ad writer Robert May contributed to the Santa Claus legend by creating the character of Rudolph the Red-Nosed Reindeer. May wrote a children's booklet for Montgomery Ward department store, telling the story of Rudolph, a reindeer who was initially ostracized due to his glowing red nose but ultimately became a hero by guiding Santa's sleigh. This charming tale not only added depth to the Santa Claus mythos but also helped to popularize Rudolph as a beloved figure in Christmas lore.