The U.S. Department of State has bought more than $70,000 worth of books authored by President Obama, sending out copies as Christmas gratuities and stocking “key libraries” around the world with “Dreams from My Father” more than a decade after its release. The U.S. embassy in Egypt, for instance, spent $28,636 in August 2009 for copies of Mr. Obama’s bestselling 1995 memoir. Six weeks earlier, the embassy had placed another order with the same book seller, Kalemat Arabia, for more than $9,000 for copies of the same book, federal purchasing records show. Around the same time, halfway around the world,...