Christmas is all about tradition—cutting down the tree, hanging the stockings, shopping with reckless abandon—and Rosemary K. Adams new book, “Historic Photos of Christmas in Chicago,” is here to celebrate it. “Working on the book,” explains Adams, “I was surprised at how our Christmas celebration has stayed the same. The world today is really different in some ways, but it is interesting to see the continuity in our Christmas traditions.” Adams’ book, laboriously compiled by a three-month hunt through the Chicago History Museum archives (“Unfortunately, there is not just one file that says ‘Christmas,’” laughs Adams), specifically highlights the history of Chicago Santas, the iconic Chicago Christmas tree (which we’ve had since 1913), Christmastime charity, decorating and (needless to say) shopping. The book, however, isn’t just a jolly peek at celebrations past, but a real black-and-white look at Christmas in Chicago-land. “My favorite photo,” Adams says, “is the one taken in 1963 which features the Chicago Christmas tree next to the flag flying half-mast. It’s a very powerful shot.”