Why was the Baton Rouge Bus Boycott significant?

Because the baton to the boycott started in 1921 and one 1920 came around before 1921 that's on rogue bus boycott

The boycott was prompted partly by the 1950 decision by the Baton Rouge City Council to support the financially strapped municipal bus company by revoking the licenses of nearly forty competing black-owned companies. African Americans had no choice but to ride segregated buses operated by the city-owned bus company.