Historical Photographs
My father was a professional photographer in Winnipeg after World War 2 ended. He started around 1947 and made a living at it until 1953. His negative collection survives, although sadly his cross reference file was used by squirrels as nesting material. The only references that remain are the occasional notes included with the negatives, and the fact that he filed them chronologically, starting a new file each week. Thus I can date most images to within a week, and occasionally add some additional data, usually if he sold the work.
Early on, Dad joined the YMCA Camera Club, and the club would schedule expeditions to various sites in and around Winnipeg.