WASHINGTON — President Barack Obama announced Thursday that major book publishers will provide more than $250 million in free e-books to low-income students and that he is seeking commitments from local governments and schools nationwide to provide library cards to all students. Obama announced the initiatives at a library in the District of Columbia’s economically depressed Anacostia neighborhood. The initiatives are tied to his ConnectEd program, a 2-year-old effort to boost educational outcomes by improving digital connectivity. “We’re going to provide millions of e-books online so that they’re available for young people who maybe don’t have as many books at home or don’t always have access to a full stock of reading materials,” Obama said during a virtual town hall sponsored by Discovery Education.