Apple is on track to become the largest private employer in Austin, Texas, after announcing plans to invest $1 billion in a new campus less than a mile away from its existing facilities there. The 133-acre site will initially be home to 5,000 new employees, with the potential to grow to 15,000. The company has also announced plans to establish new sites in Seattle, San Diego and Culver City and expand in cities across the United States including Pittsburgh, New York and Boulder, Colorado over the next three years, with the potential for additional expansion elsewhere in the US over time.