Era guide · 1907–1915
Divided Back era (the Golden Age)
The divided back — message left, address right — arrived in the US in March 1907 and set off the greatest postcard craze in history. Billions of cards moved through the mails; collecting albums sat in ordinary parlors; and the finest printing came from Germany, whose lithographers around Saxony and Bavaria produced much of the era's output even for American publishers.
That German connection is a dating tool. The Payne-Aldrich Tariff of 1909 made imported cards more expensive, and the First World War then severed the trade entirely. A “Printed in Germany” imprint on a divided-back card places it almost certainly before 1915 — and the era's end is really the war's beginning.
Golden-age images typically run to the card's edges (no white border), the stock is thin and the lithography fine. If your divided-back card is an actual photograph rather than a printed image, it's a real photo postcard — date it by its stamp box instead.