Several of the Smithsonian Institution's new initiatives received generous support, and an invigorating boost, from a $50 million gift from the Bill & Melinda Gates Foundation.

The gift, announced Wednesday night by the Smithsonian, sets aside $30 million to create the Youth Access Endowment. While the Smithsonian had 30 million visitors in 2009 and has had 24.4 million so far this year, the museum seeks to reach youth who have few opportunities to visit it.

"Our responsibility is to reach people where they are," said Claudine K. Brown, the assistant secretary for education and access, a new office created to develop outreach programs. "The primary concern on the Gateses' part and ours is that we would be able to reach students in states where the schools are under-resourced." Experts from throughout the Smithsonian will help develop materials, both print and online, for various school systems. "Washington, D.C., is one of those communities," Brown said.

Over the years, the Smithsonian has developed teacher materials, learning tools for various grades and online conferences through its Web site, which received 136 million visits from January to September of this year. The new money will finance projects developed by Smithsonian researchers on a competitive basis, with a goal of creating a Smithsonian-led education community. "We are encouraging Smithsonian educators and their partners to work with colleagues outside the museum who might have the expertise they don't have," Brown said.

The Gates Foundation is the largest in the world with $35 billion.

The total Gates gift is the largest the Smithsonian has received since 2005.

The Smithsonian has used large gifts in the past to jump-start projects. Kenneth E. Behring, a California businessman and philanthropist, gave $100 million from 1997 to 2000, which supported the renovation of the National Museum of Natural History's rotunda, as well as the extensive remodeling of the National Museum of American History. Starting in 1999, Steven F. Udvar-Hazy, a California aircraft leasing executive, gave more than $65 million toward the construction of the companion building to the National Air and Space Museum near Dulles International Airport. Five years ago, the Donald W. Reynolds Foundation gave $45 million for the renovation of the Smithsonian American Art Museum and the National Portrait Gallery.

A $10 million portion of the Gates donation goes to support four broad strategies announced by Secretary G. Wayne Clough earlier this year. Understanding the American experience, valuing world cultures, understanding and sustaining a biodiverse planet and unlocking the mysteries of the universe are four themes that Smithsonian will highlight in its research and exhibitions.

The remaining $10 million, which was announced a year ago, supports the construction and design phase of the National Museum of African American History and Culture. The museum is expected to open on the Mall in 2015.