John Armstrong bought the Philadelphia Place acreage for $276 an acre, the land comprising original land grants from the Republic of Texas. Armstrong formed a realty company with sons-in-law Hugh Prather and Edgar Flippen. That fall, they went to California and hired a planner named Wilbur David Cook who had just laid out a community named Beverly Hills. Cook completed a master plan in six months, using 20% of the land for parks and green space. The new residential development was named Highland Park.