Question: United Airlines and Boeing were both formed by who?

Context paragraphs:
Connexion by Boeing: Connexion by Boeing (CBB) was an in-flight online internet connectivity service from Boeing.  This service allowed travellers to access a high-speed internet connection while on board a plane in flight through a wired Ethernet or a wireless 802.11 Wi-Fi connection.  Connexion by Boeing was formed as a separate business unit of The Boeing Company.  Major development on the service commenced with a partnership agreement between United Airlines, Delta Air Lines, and American Airlines on June 13, 2001.  Lufthansa joined the partnership as the International launch customer on June 17, 2001.  United, Delta, and American subsequently withdrew from the partnership after the 9/11 terrorist attacks due to the severe drop in airline travel that occurred after the attacks.

United Airlines Flight 93: United Airlines Flight 93 was a domestic scheduled passenger flight that was hijacked by four Al-Qaeda terrorists on board, as part of the September 11 attacks.  It crashed into a field in Somerset County, Pennsylvania, during an attempt by the passengers and crew to regain control.  All 44 people aboard were killed, including the four hijackers, but no one on the ground was injured.  The aircraft involved, a Boeing 757–222, was flying United Airlines' daily scheduled morning flight from Newark International Airport in New Jersey to San Francisco International Airport in California.

History of United Airlines: United Airlines is the 6th largest airline in the world, with 86,852 employees (which includes the entire holding company United Continental Holdings) and 721 aircraft.  It was the brainchild of William Boeing and emerged from his consolidation of numerous carriers and equipment manufacturers from 1928 to 1930.

National Air Transport: National Air Transport was a large United States airline.  It was the first airline to operate cross country flights.  In 1930 it was bought by Boeing.  The Air Mail Act of 1934 prohibited airlines and manufacturers from being under the same corporate umbrella, so Boeing split into three smaller companies, one of which is United Airlines, and it is this that included what had previously been National Air Transport.

Boeing 720: The Boeing 720 is a four-engine narrow-body short- to medium-range passenger jet airliner.  Developed by Boeing in the late 1950s from the Boeing 707, the 720 has a shorter fuselage and less range.  The 720 first flew in November 1959 and the model entered service with launch customer United Airlines in July 1960.

Planning of the September 11 attacks: On September 11, 2001, 19 Arab-Muslim hijackers took control of four commercial aircraft and used them as suicide weapons in a series of four coordinated acts of terrorism to strike the World Trade Center in New York City, the Pentagon in Arlington County, Virginia, and an additional target in Washington, D.C. Two aircraft hit the World Trade Center while the third hit the Pentagon.  However, one plane never arrived at its target; it crashed in a field in Pennsylvania because the passengers fought back.  The intended target is believed to have been either the United States Capitol or the White House.  As a result, 2,977 victims were killed, making it the most deadly terrorist attack on U.S. soil; also the deadliest foreign attack on U.S. soil, exceeding Japan's surprise attack on Pearl Harbor in Honolulu, Hawaii, on December 7, 1941, which killed 2,403 victims.  It was carefully planned by al-Qaeda, who sent 19 terrorists to take over Boeing 757 and Boeing 767 aircraft, operated by American Airlines and United Airlines.

China Aircraft Services Limited: CASL was founded in 1995 as a joint venture among Air China Group (via CNAC(G)), British Airways, Hutchison Whampoa (China), and United Airlines.  Since the 2005, it has been a joint venture among Air China Group (40%), Hutchison Whampoa China (20%), United Airlines (20%), and China Airlines (20%).  China Airlines acquired 13.33% stake from CNAC(G) in 2005 (which was acquired from British Airways in 2003) and 6.67% from Hutchison Whampoa China.  Since 2015, Hutchison Whampoa China became a wholly owned subsidiary of CK Hutchison Holdings.

Air Wisconsin: Air Wisconsin Airlines is a regional airline based at Appleton International Airport in the town of Greenville, Wisconsin, United States, near Appleton.  Air Wisconsin is the largest privately held regional airline in the United States.  It currently operates regional jet flights as American Eagle under contract to American Airlines via a code sharing agreement, serving cities in the U.S. and Canada with hubs at Boston Logan International Airport (BOS), Charlotte Douglas International Airport (CLT), Philadelphia International Airport (PHL) and Ronald Reagan Washington National Airport (DCA) .  Air Wisconsin previously operated United Express service on behalf of United Airlines followed by US Airways Express service on behalf of US Airways prior to becoming an American Eagle regional air carrier.  The company has announced it will once again partner with United Airlines as a United Express code sharing air carrier with primary hubs to be located at Chicago O'Hare International Airport (ORD) and Washington Dulles International Airport (IAD) beginning in September 2017 and will be "exclusively operating" as United Express by March 2018.

William Boeing: William Edward Boeing ( ; October 1, 1881 – September 28, 1956) was an American aviation pioneer who founded The Boeing Company.

Boeing Model 40: The Boeing Model 40 was a United States mail plane of the 1920s.  It was a single-engined biplane that was widely used for airmail services in the United States in the 1920s and 1930s, especially by airlines that later became part of United Airlines.  It became the first aircraft built by the Boeing company to carry passengers.

Supporting paragraphs: History of United Airlines William Boeing
Answer: William Boeing