Oslin graduated from Mercer University and the Graduate School of Journalism at Columbia University. He was a reporter for the "Newark Star-Ledger" and the "Newark Evening News". As a reporter, he covered the Lindbergh kidnapping and the Hindenburg disaster. He was public relations director for Western Union, where he invented the singing telegram in 1933. At Oslin's suggestion, the first singing telegram was delivered to singer Rudy Vallee on July 28, 1933 for his birthday. While Oslin created the singing telegram because he thought "that messages should be fun," he recalled that he "was angrily informed I was making a laughingstock of the company."