Frustrated by the President 's refusal to declare the statehood of Colorado , Congress approves a Colorado Statehood Bill .
President Andrew Johnson vetoes the measure on 1866 - 05 - 15 .
Frustrated by the President 's refusal to declare the statehood of Colorado , Congress approves a Colorado Statehood Bill , but President Andrew Johnson vetoes the measure on 1866 - 05 - 15 .