<Tr> <Th> Daily traffic </Th> <Td> 17,720 </Td> </Tr> <P> The Edmund Pettus Bridge carries U.S. Route 80 Business (US 80 Bus .) across the Alabama River in Selma, Alabama . Built in 1940, it is named after Edmund Winston Pettus, a former Confederate brigadier general, U.S. Senator from Alabama, and Grand Dragon of the Alabama Ku Klux Klan . The bridge is a steel through arch bridge with a central span of 250 feet (76 m). There are nine large concrete arches supporting the bridge and roadway on the east side . </P> <P> The Edmund Pettus Bridge was the site of the conflict of Bloody Sunday on March 7, 1965, when armed police attacked Civil Rights Movement demonstrators with billy clubs and tear gas as they were attempting to march to the state capital Montgomery . The marchers crossed the bridge again on March 21 and successfully walked to the Capitol building . </P> <P> The bridge was declared a National Historic Landmark on March 11, 2013 . </P>

How would we classify the selma march upon the edmund pettus bridge
find me the text answering this question