Ar'bor Day, a day designated by legislative enactment in many states for the voluntary planting of trees by the people. It was inaugurated in 1874 by the Nebraska state board of agriculture, at the suggestion of J. Sterling Morton, afterwards secretary of agriculture in President Cleveland's second administration. Nearly every one of the states has since established an annual Arbor Day and observes it as a legal holiday, the school children being generally prepared for a special observance of the occasion. Bird Day is also now associated with Arbor Day, its purpose being to instruct children in the care and protection of birds. Several states publish manuals of exercises and instructions for the day's observance in the schools.