The Black Hills Expedition was a United States Army expedition in 1874 led by Lieutenant Colonel George Armstrong Custer that set out on July 2, 1874 from modern day Bismarck, North Dakota, which was then Fort Abraham Lincoln in the Dakota Territory, with orders to travel to the previously uncharted Black Hills of South Dakota.
 Its mission was to look for suitable locations for a fort, find a route to the southwest, and to investigate the possibility of gold mining.
 Custer and his unit, the 7th Cavalry, arrived in the Black Hills on July 22, 1874, with orders to return by August 30.
 The expedition set up a camp at the site of the future town of Custer; while Custer and the military units searched for a suitable location for a fort, civilians searched for gold, and it is disputed whether or not any substantial amount was found.
 Nonetheless, this prompted a mass gold rush which in turn antagonised the Sioux Indians who had been promised protection of their sacred land through Treaties made by the US government, and who were later to kill Custer at the Battle of the Little Big Horn in the Great Sioux War of 1876–1877 between themselves and the United States.
A notice of proposed rulemaking (NPRM) is a public notice issued by law when one of the independent agencies of the United States government wishes to add, remove, or change a rule or regulation as part of the rulemaking process.
 It is an important part of United States administrative law which facilitates government by typically creating a process of taking of public comment.
 This nomenclature is also utilized at the state level.
Alexander Hamilton (January 11, 1755 or 1757July 12, 1804) was an American statesman and one of the Founding Fathers of the United States.
 He was an influential interpreter and promoter of the U.S. Constitution, as well as the founder of the nation's financial system, the Federalist Party, the United States Coast Guard, and "The New York Post" newspaper.
 As the first Secretary of the Treasury, Hamilton was the main author of the economic policies of the George Washington administration.
 He took the lead in the funding of the states' debts by the Federal government, as well as the establishment of a national bank, a system of tariffs, and friendly trade relations with Britain.
 His vision included a strong central government led by a vigorous executive branch, a strong commercial economy, with a national bank and support for manufacturing, plus a strong military.
 This was challenged by Virginia agrarians Thomas Jefferson and James Madison, who formed a rival party, the Democratic-Republican Party.
 They favored strong states based in rural America and protected by state militias as opposed to a strong national army and navy.
 They denounced Hamilton as too friendly toward Britain and toward monarchy in general, and too oriented toward cities, business and banking.
George Drouillard (1773–1810) was a civilian interpreter, scout, hunter, and cartographer, hired at the age of 30 for Lewis and Clark's Voyage of Discovery to explore the territory of the Louisiana Purchase in 1804–1806, in search of a water route to the Pacific Ocean.
 He later worked as a guide and trapper for Manuel Lisa on the upper Missouri River, joining his Missouri Fur Company in 1809.
 Drouillard was believed to have been killed in what is now the state of Montana while trapping beaver, in an attack by the Blackfeet or Gros Ventre tribes.
The Supreme Court of the United States is the highest federal court of the United States.
 Established pursuant to Article Three of the United States Constitution in 1789, it has ultimate (and largely discretionary) appellate jurisdiction over all federal courts and state court cases involving issues of federal law plus original jurisdiction over a small range of cases.
 In the legal system of the United States, the Supreme Court is generally the final interpreter of federal law including the United States Constitution, but it may act only within the context of a case, in which it has jurisdiction.
 The Court does not have power to decide political questions, and its enforcement arm is in the executive rather than judicial branch of government.
The 541st Parachute Infantry Regiment was an airborne infantry regiment of the United States Army, activated during World War II.
 While never destined to see combat the regiment was composed of highly trained and highly educated troopers.
 It was also utilized to send trained replacements overseas.
The Away from Home Tour, also marketed as the Light Dreams and Nightmares Tour, was the first headlining concert tour by Canadian recording artist, Drake.
 It began on April 5, 2010 in Slippery Rock and continued until November 6, 2011 with its final show scheduled in Las Vegas.
 Scheduled for 78 performances across the United States and Canada, the tour was also utilized as a part of an environmentally friendly campaign alongside non-profit organization Reverb.
The Corps of Discovery was a specially-established unit of the United States Army which formed the nucleus of the Lewis and Clark Expedition that took place between May 1804 and September 1806.
 The Corps, which was a select group of volunteers, were led jointly by Captain Meriwether Lewis and Second Lieutenant William Clark.
 Commissioned by President Thomas Jefferson, the Corps' objectives were both scientific and commercial – to study the area's plants, animal life, and geography, and to learn how the Louisiana Purchase could be exploited economically.
The Red River Expedition, also known as the Freeman-Custis Expedition, Freeman Red River Expedition, Sparks Expedition, or officially as the Exploring Expedition of Red River in 1806, was one of the first civilian scientific expeditions to explore the Southwestern United States.
 It was ordered to find the headwaters of the Red River (Red River of the South) from the Mississippi River as a possible trading route to Santa Fe, then under Spanish colonial control in New Mexico; to contact Native American peoples for trading purposes; to collect data on flora, fauna, and topography, and map the country and river; and to assess the land for settlement.
 The Spanish officials intercepted the expedition 615 miles upriver, in what is now northeastern Texas, and turned it back before the party achieved all of its goals.
The primary mission of the 123rd CRG is to provide rapidly deployable forces to the United States Air Force to open forward airfields in an expeditionary environment as a completely self-contained unit.
 In addition, due to its unique mobile capability, the 123rd CRG is also utilized to provide quick reaction logistical support for humanitarian missions including man-made and natural disasters.

Question: George Drouillard was an interpreter in an expedition which also utilized a specially-established unit of which United States miltary branch?
Answer: Army