ARLINGTON, Virginia (CNN) -- Barack Obama marked his first Memorial Day as president on Monday, calling on Americans to remember U.S. troops who died in the service of their country and navigating a Civil War memorial controversy. President Obama pays tribute to veterans at a wreath-laying at Arlington National Cemetery on Monday. The president participated at the 141st annual Memorial Day wreath-laying ceremony at Arlington National Cemetery's Tomb of the Unknowns. The men and women buried at Arlington "waged war so that we may know peace," Obama said. "They were willing to give up everything for the defense of our freedom [and] were willing to sacrifice all for their country. ... They are the best of America."
@highlight
Obama continues controversial sending of wreath to Confederate Memorial
@highlight
President also sends wreath to African-American Civil War Memorial
@highlight
Obama takes part in Memorial Day wreath-laying at Arlington National Cemetery
@highlight
Men and women buried there "waged war so that we may know peace," he said
Memorial Day was first marked May 30, 1868, three years after the end of the @placeholder.