In the United States there exists five branches of military service: the U.S. Army, U.S. Navy, U.S. Air Force, U.S. Marine Corps, and the U.S. Coast Guard.
The Coast Guard originated August 4, 1790, when the first Congress of the United States passed Alexander Hamilton's "Revenue Act." Under its authority, there was created the first Federal armed service: the Revenue Marine, later known as the Revenue Cutter Service. Its purpose was to suppress smuggling and to enforce the provisions of the Revenue Act, and for this reason, it was placed under the Treasury Department. Hamilton urged that its officers be commissioned and that the service be established with the full honor of the military tradition. Thus, he maintained, "will not only induce fit men the more readily to engage, but will attach them to their duty by a nicer sense of honor."

President Washington issued the first commission to Hopley Yeaton, of New Hampshire, to command "a cutter in the Service of the United States of America." This was the first commission issued to a seagoing officer under the Constitution. From the start, the revenue Cutter Service was a fighting unit. Until 1798, when the Navy was organized, the six revenue cutters built by authority of the Act of 1790, were our only public warships. They performed valiant service during our undeclared war with France, 1799-1800, and the Service has maintained its reputation as a combatant force in every subsequent war in which the United States has been engaged, including Viet-Nam and the Persian Gulf War.

Origin of the Life-Saving Service
 Towards the end of the Eighteen Century, the rising tide of the humanitarian movement reached the hazardous profession of the mariner. In 1774, the Royal Humane Society was established in Great Britain for the purpose of saving lives at sea., The idea spread rapidly, especially among maritime nations. As early as 1785, the Massachusetts Humane Society was founded. This organization built houses of refuge along the coast for shipwrecked mariners, and in 1807, began to put lifeboats in them. It was, however, another forty years before the Unites States Government became sufficiently interested to create an official service for the purpose.
 In 1848, Congress appropriated $10,000 to build eight small boathouses along the beach of New Jersey. This marked the beginning of the Life-Saving Service. In 1878, the Service was reorganized and established as a regular unit in the Treasury Department. On January 28, 1915, the Life-Saving Service was merged with the Revenue Cutter Service and the combined organization was given the new name of United States Coast Guard. On March 17 of the same year, the "United States Coast Guard" made its first rescue at Coast Guard Station Cape Lookout, North Carolina.

Origin of the Lighthouse Service
 In colonial days, several of the American Colonies established lighthouses as aids to navigation. The first was the Boston Light, built in 1716. In those days it was nothing more than a whale-oil lamp, without chimney, protected by glass windows. By 1789, there were a dozen lighthouses in the Thirteen States. In that year the first Congress under the Constitution took over the existing lighthouses and authorized the construction of the first federal lighthouse at Cape Henry, Virginia. From 1789, then, the Lighthouse Service may be said to have begun.
 During the next decade the number of lighthouses increased to two dozen, and during the early part of the nineteenth century, they were constructed at a rapid rate, but they were limited of limited service until the advent of Fresnel lenses. This type of lens, by means of a series of glass echelons, gathered the rays from the oil lamp into a horizontal beam, and by means of prisms projected the beam many miles. The first Fresnel lens to be installed in the United States was at the Navesink Lighthouse in 1841. From then on, the service grew by leaps and bounds.
 In the course of the nineteenth century, the Lighthouse Service also set out an ever-increasing number of buoys, lights, and beacons as further aids to navigation. From the start, the Service was a part of the Treasury Department, but in 1903 it was transferred to the Commerce Department. On July 1, 1939, by executive order, the Lighthouse Service was withdrawn from that department and incorporated with the United States Coast Guard.

World War II
 With the prospect of war approaching, Congress deemed it necessary to augment the U.S. Coast Guard with a civilian stand-by force. Although officially set as a boater assist group, its underlining purpose was probably that of a "Home Guard" type of force, similar to that organized in England, since it was made up of primarily former Coast Guard personnel.
 On June 23, 1939, Congress passed Title 14 of the U.S. Code, establishing the U.S. Coast Guard Auxiliary. Initially, the organization was called the Coast Guard Reserve. With the entrance of the United States into World War II, the civilian Coast Guard Reserve was renamed the Coast Guard Auxiliary, with the Coast Guard Reserve being formed as a military reserve force.
 After the entry of the United States into World War II, the Coast Guard was temporarily assigned to the War Department (now called the Defense Department), and was under the jurisdiction of the Department of the Navy for the duration of the war. (The Coast Guard, or select units therein, is always transferred to the Department of the Navy during times of war.)

 Members of the Coast Guard Auxiliary who volunteered to serve as Temporary Members of the Coast Guard Reserve, augmented the Coast Guard with off shore and harbor patrols, freeing up the regular Coast Guard for regular naval duties, some of which included manning landing craft during all the major invasions, including the Normandy Invasion.
Women joined the Coast Guard as SPARS in 1942. By the time World War II ended, there were more than 10,000 SPARS officers and enlisted women. The title SPARS comes from the initial letters of the Coast Guard's Latin motto and its meaning in English:

  "Semper Paratus -- Always Ready"