Bob Kemper, in the Atlanta Journal-Constitution (June 8, 2004):

Those who planned Lincoln's funeral in 1865 had to look to European and Masonic rituals in creating the American state funeral, according to historians. Many of the rituals of Reagan's funeral, such as the inclusion of a riderless horse in the funeral procession, are rooted in rituals that date back to the days of Genghis Kahn and the Roman Empire.

A warrior's horse was once sacrificed at the time of his burial so that it could meet him in the afterlife and allow him to ride into heaven.

In the same vein, a caisson designed for a 75 mm cannon will carry Reagan's casket much as they once were used to evacuate the dead from battlefields.

Three volleys will be fired over Reagan's grave to mark the end of the service, just as three volleys indicated Civil War soldiers had completed services for their fallen brethren and were ready again to engage the enemy.