After three days of turbulent meetings, the Texas Board of Education on Friday approved a social studies curriculum that will put a conservative stamp on history and economics textbooks, stressing the superiority of American capitalism, questioning the Founding Fathers' commitment to a purely secular government and presenting Republican political philosophies in a more positive light. The vote was 10-5 along party lines, with all the Republicans on the board voting for it. The board, whose members are elected, has influence beyond Texas because the state is one of the largest buyers of textbooks. In the digital age, however, that influence has diminished as technological advances have made it possible for publishers to tailor books to individual states. In recent years, board members have been locked in an ideological battle between a bloc of conservatives who question Darwin's theory of evolution and believe the Founding Fathers were guided by Christian principles, and a handful of Democrats and moderate Republicans who have fought to preserve the teaching of Darwinism and the separation of church and state. Since January, Republicans on the board have passed more than 100 amendments to the 120-page curriculum standards affecting history, sociology and economics courses from elementary to high school. The standards were proposed by a panel of teachers. 'We are adding balance,' said Don McLeroy, the leader of the conservative faction on the board, after the vote. 'History has already been skewed. Academia is skewed too far to the left.' Battles over what to put in science and history books have taken place for years in the 20 states where state boards must adopt textbooks, most notably in California and Texas. But rarely in recent history has a group of conservative board members left such a mark on a social studies curriculum. The curriculum standards will now be published in a state register, opening them up for 30 days of public comment. A final vote will be taken in May, but given the Republican dominance of the board, it is unlikely that many changes will be made. The standards, reviewed every decade, serve as a template for textbook publishers, who must come before the board next year with drafts of their books. The board's makeup will have changed by then because McLeroy lost in a primary this month to a more moderate Republican, and two others -- one Democrat and one conservative Republican -- announced they were not seeking re-election. 