Given the task definition and input, reply with output. In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.

Passage: Jim Brandenburg was born and raised in Luverne, Minnesota in the farms and prairies of Southwestern Minnesota, USA. After studying at Worthington Community College, he went on to attend the University of Minnesota Duluth, where he majored in art history and worked for the local public television station. Upon graduating, he returned to Worthington, Minnesota and began working as a photojournalist for the Worthington Daily Globe. Within months, he began submitting work to the National Geographic Society as a freelance photographer, and in 1978 he became a contract photographer for National Geographic Magazine. Additionally, his photography has been published in a number of National Geographic Society books including "Journey Into China", "Heart of a Nation" and "Discovering Britain and Ireland", in which his photos of the Highlands in Scotland were featured.
Link Information: in 1978 he became a contract photographer for National Geographic Magazine. Answer: 1888,
When was the periodical that Brandenburg became a contract photographer for in 1978 first published?