Alaska high school students would be required to complete a civics education course or receive a passing score on a civics assessment exam to graduate if the state House next year accepts legislation approved by the Senate.

Senators unanimously approved the bill on May 5, and the House could take up the measure next year.

The legislation comes as recent national data shows the first-ever decline in U.S. eighth grade students’ history and civics test scores, according to the National Assessment of Educational Progress, which released the data May 3.

According to the data, nearly one-third...