The city of San Diego is located in the southwest corner of the United States in a place that the Diegueño Indians once called home. The Spanish also favored the location because the area had a naturally deep bay. After locating the harbor, Spanish soldiers settled in the area and built the first presidio (fort). A mission was founded by Father Junípero Serra in 1769. It was given the name San Diego de Alcalá, after a Spanish saint. San Diego is considered to be the birthplace of California. Throughout the late 1700s, residents struggled to keep businesses viable, then turned to trading cattle during the early 1800s. The new economic strategy turned out to be a good choice; cattle became one of the most important activities of the area. It was not until 1834 that the California community was officially organized as a town. It became a full-fledged city in 1850. At that time, the city had little beyond the cattle trade to offer newcomers — and a harbor ready to be exploited. Five years after San Diego became a city, the California Southern Railroad laid tracks to the community in hope of taking advantage of the harbor. The new plan worked in the railroad company's favor by enabling them to utilize newly available resources. The railroad was not only an advantage for the fledgling industrial base, but it created a new way for the general public to get across the country with ease. The railroad created a land boom. People quickly bought up land in anticipation of the new businesses anticipated to arrive in San Diego. A sampler of area attractions includes the Convention and Performing Arts Center, Civic Theatre, Cabrillo National Monument, commemorating Juan Rodrígues Cabrillo, the Portuguese explorer who sailed into San Diego Bay in 1542; Mission Bay Park, the largest of 120 parks; Sea World Aquarium, and the San Diego Zoo. The Qualcomm Stadium in Mission Valley is home to the San Diego Chargers and the San Diego Padres.