The mid-1880s brought dramatic changes in Edison's life. The first of these changes was the death of his first wife, Mary Stilwell, on August 9, 1884. Stilwell died at the age of twenty-nine, leaving Edison a widower at thirty- seven years old. Since he was still fairly young and possessed of a large personal fortune, he was quickly barraged by offers of "sympathy" from young women. The one who caught his eye was Mina Miller, a nineteen-year-old from a well-off Boston family. They met in the winter of 1885 and were married on February 24, 1886.
Mina Miller was a more assertive woman than Mary Stilwell and proved to be an invaluable companion to Edison. To occupy herself during her husband's long absences, she was active in the community. She also raised their three children–Madeline, Charles, and Theodore–in their new house in West Orange, New Jersey.
1886 was also the year Edison opened his new research laboratory in West Orange. Having outgrown the Menlo Park facility, Edison set about building a three-story building with an attached powerhouse comprising more than 50,000 square feet of floor space. The new facility had an emphasis on manufacturing and business as opposed to invention. These new directions complemented the turn of Edison's career. Still, important new inventions came out of the West Orange facility, such as the Kinetoscope and the dictating machine. Edison also perfected the phonograph and the electrical light system at West Orange.
Patent battles and competition with George Westinghouse temporarily slowed Edison's research on electrical light systems, but competition spurred his research on the phonograph. Because it had yet to provide much income and was still widely considered to be a toy, Edison had let the phonograph languish. But Alexander Graham Bell, distraught that he had not invented one first, saw great market potential in the device. In 1885 he and two of his colleagues applied for a patent on their invention, the "graphophone." The graphophone depended heavily upon Edison's phonograph technology.
Bell then approached Edison with a proposition to jointly market an improved phonograph. Edison, furious, set his energy to improving the phonograph. He produced several new models in the early 1890s and searched for a dependable power source that would make the device useful for the home market. He found the perfect match of consumer demand and high quality in 1896, when he began marketing a forty-dollar spring-motor phonograph, and sales skyrocketed into the early 20th century.
Less successful were Edison's forays into the ore-milling business. Edison first became interested in ore-milling in 1880. In the course of developing his electric light system, he invented and patented a magnetic separator for iron ore. His hope was to develop a competitor to ore mines for the east coast market. He set up plants as early as the summer of 1881 but did not devote himself fully to the project until January 1889.