Redwood National Park was created in 1968, by Congress, in order to assure the preservation of these old and mighty forests. The Redwood trees are more than 2,000 years old, and can grow to more than 300 feet tall. When Redwood harvesting began in the early 1850s, there was more than two million acres of old-growth Redwood forests in existence. But Euro-Americans took less than 60 years to reduce the Redwood forest to just a few hundred thousand acres. By the late 1910s, a preservationist group called the "Save-the-Redwoods League," started purchasing large tracts of Redwood acreage in an effort to save the quickly disappearing forests. The State of California pledged to match funds put forth by the league, and between 1920 and 1960, more than 100,000 acres were set aside for preservation through this partnership. In the early 1920s, California established the three state parks, as well as Humboldt Redwoods State Park to the south, with the purchased lands. The state park system has protected the parks’ natural and cultural resources, and has welcomed visitors to explore and marvel at the Redwood groves and surrounding ecosystems. However, logging continued outside the state parks, and with the passing years, conventional thinking about the environment had changed, and in the 1960s, more emphasis was placed upon the importance of preserving whole ecosystems as opposed to just portions of ecosystems. With help from the Sierra Club and the National Geographic Society, the Save-the-Redwoods League now called on Congress to create a national park that would include land in the Redwood Creek area adjacent to the state parks. By then, 90 percent of the original redwoods had been logged and after much controversy and compromise with timber companies, Congress finally approved a federal park. President Lyndon B. Johnson signed into law the act that established Redwood National Park. The new preserve placed 58,000 acres in the care of the National Park Service. Some of Redwood National Park included state park lands, which were still under state jurisdiction. In 1977, Representative Phillip Burton introduced legislation to expand the federal park. Despite opposition from the timber industry, in March 1978, President Jimmy Carter signed into law the addition of 48,000 acres to Redwood National Park. This widened the protection in Redwood Creek, although 39,000 acres of the addition were already logged over. In 1994, the NPS and CDPR agreed to jointly manage the four parks for the best resource protection possible.