1892 Horticulturist Kate O. Sessions was given 30 acres in City Park, as it was known, for a private nursery. In return, she planted 100 trees a year in the Park and 300 trees and other plants throughout San Diego. Sessions became known as the "mother of Balboa Park" because of her many plantings and exotic plant introductions to the area.

1903 The first master plan was prepared for Park improvements and beautification.

1905 A City tax was levied to support the Park’s master plan.

1903–1910 Planting continued, water systems were installed, and roads were built. The Park began to look much like it does today.

1910 A contest was held to rename City Park. The winning entry was Balboa Park, suggested because the Park offered a wide view of the Pacific Ocean, and explorer Vasco Núñez de Balboa was the first European to see the Pacific.

1915–1916 The Panama-California Exposition, honoring the completion of the Panama Canal, was held in the Park. The purpose of the Expo was "to illustrate the progress and possibility of the human race...." Displays and demonstrations included the latest in agricultural, industrial, horticultural, and technological inventions and refinements.

The Spanish Colonial Revival style prevailed in the building designs for this Expo, which were undertaken by the well-known architect Bertram Grosvenor Goodhue. Completed for this exposition were Cabrillo Bridge, the California Building, the House of Charm, the House of Hospitality, the Casa de Balboa, the Casa del Prado, the Balboa Park Club, the Spreckels Organ Pavilion, the Botanical Building, and Alcazar Garden. The California Building and Spreckels Organ Pavilion were the only buildings designed for permanent use.

1916 Dr. Harry Wegeforth, a surgeon for the fair, conceived the idea of starting a zoo after hearing the roar of a lion, one of the few wild animals displayed in cages at the Expo. Wegeforth became the San Diego Zoo’s first president and remained in office until his death in 1941.

1926 The San Diego Museum of Art opened in a building designed by architect William Templeton Johnson and Robert W. Snyder, architect and builder.

1933 The Natural History Museum opened. Its building was also designed by William Templeton Johnson.

1935–1936 As a way of bolstering local economy, San Diego held the California-Pacific International Exposition in the Park. Many exhibits came directly from the Chicago World’s Fair. The Expo’s architect, Richard Requa, designed buildings inspired by the native architecture of the Southwest–the Indian pueblos as well as the earlier Aztec and Mayan structures in Yucatan and Mexico. These buildings, along with those constructed for the 1915 Expo, present a complete architectural history of the Southwest from prehistoric times to modern day.

Most of the buildings in the Park’s Southern Palisades area were constructed for this fair: the Conference Building, the Ford Building, the Starlight Bowl and the Municipal Gymnasium. Other buildings constructed at this time were the Spanish Village Art Center, the House of Pacific Relations (seventeen cottages) and the United Nations Building.

The Old Globe Theatre–a replica of the 16th-century Elizabethan Globe Theatre, once located in central London on the Thames River–was built for this second exposition.

1965 The Timken Museum of Art opened in a building designed by architect Frank Hope.

1973 The Reuben H. Fleet Science Center, containing the country’s first IMAX® Dome theater, opened to visitors.

1988 The San Diego Automotive Museum opened to the public in the Conference Building.

1996 The Mingei International Museum opened in the newly reconstructed House of Charm.

1999 The San Diego Hall of Champions opens in the reconstructed Federal Building

2001 The San Diego Natural History Museum opens after reconstruction and remodeling.

(*Text Borrowed with permission From Balboa Park Webpage: http://www.balboapark.org/info.html#parkhist)