With the appearance of the Soviet Mikoyan-Gurevich MiG-15 in combat over North Korea in 1950, USAF propeller-driven bombers were rendered obsolete as strategic offensive weapons.
Both the B-36 and the B-29/B-50 Superfortresses were designed during World War II, prior to the jet age.
A new generation of swept-wing jet bombers, able to fly higher and faster, was needed to effectively overcome the MiG-15 or subsequent Soviet interceptors if the Cold War escalated into armed conflict.

After fighting in Korea had ceased, President Eisenhower called for a "new look" at national defense.
His administration chose to invest in the USAF, especially SAC, retiring nearly all of its B-29/B-50s in favour of the new Boeing B-47 Stratojet.
By 1955, the swept-wing Boeing B-52 Stratofortress was entering the inventory in substantial numbers, which replaced B-36s.

Two major factors contributing to the obsolescence of the B-36 and its phaseout were a lack of aerial refueling capability (instead requiring intermediate refueling bases to reach planned targets deep in the Soviet Union.)
and its slow speed (making it vulnerable to jet interceptors and thus severely decreasing its likelihood of reaching targets in Soviet territory.

The scrapping of B-36s began in February 1956.
Once replaced by B-52s, they were flown directly from operational squadrons to Davis–Monthan AFB, Arizona, where the Mar-Pak Corporation handled their reclamation and destruction.
Defense cutbacks in FY 1958 compelled the B-52 procurement process to be stretched out and the B-36 service life to be extended.
The B-36s remaining in service were supported with components scavenged from aircraft sent to Davis–Monthan.
Further update work was undertaken by Convair at San Diego (Specialized Aircraft Maintenance, SAM-SAC) until 1957 to extend the life and capabilities of the B-36s.
By December 1958, only 22 B-36Js were still operational.

On 12 February 1959, the last B-36J built, AF Ser.
No.
52-2827, left Biggs AFB, Texas, where it had been on duty with the 95th Heavy Bombardment Wing, and was flown to Amon Carter Field in Fort Worth, where it was put on display.
Within two years, all B-36s, except five used for museum display, had been scrapped at Davis–Monthan AFB.
With the appearance of the Soviet Mikoyan-Gurevich MiG-15 in combat over North Korea in 1950, USAF propeller-driven bombers were rendered obsolete as strategic offensive weapons. Both the B-36 and the B-29/B-50 Superfortresses were designed during World War II, prior to the jet age. A new generation of swept-wing jet bombers, able to fly higher and faster, was needed to effectively overcome the MiG-15 or subsequent Soviet interceptors if the Cold War escalated into armed conflict.
After fighting in Korea had ceased, President Eisenhower called for a "new look" at national defense. His administration chose to invest in the USAF, especially SAC, retiring nearly all of its B-29/B-50s in favour of the new Boeing B-47 Stratojet. By 1955, the swept-wing Boeing B-52 Stratofortress was entering the inventory in substantial numbers, which replaced B-36s.
Two major factors contributing to the obsolescence of the B-36 and its phaseout were a lack of aerial refueling capability (instead requiring intermediate refueling bases to reach planned targets deep in the Soviet Union.) and its slow speed (making it vulnerable to jet interceptors and thus severely decreasing its likelihood of reaching targets in Soviet territory.
The scrapping of B-36s began in February 1956. Once replaced by B-52s, they were flown directly from operational squadrons to Davis–Monthan AFB, Arizona, where the Mar-Pak Corporation handled their reclamation and destruction. Defense cutbacks in FY 1958 compelled the B-52 procurement process to be stretched out and the B-36 service life to be extended. The B-36s remaining in service were supported with components scavenged from aircraft sent to Davis–Monthan. Further update work was undertaken by Convair at San Diego (Specialized Aircraft Maintenance, SAM-SAC) until 1957 to extend the life and capabilities of the B-36s. By December 1958, only 22 B-36Js were still operational.
On 12 February 1959, the last B-36J built, AF Ser. No. 52-2827, left Biggs AFB, Texas, where it had been on duty with the 95th Heavy Bombardment Wing, and was flown to Amon Carter Field in Fort Worth, where it was put on display. Within two years, all B-36s, except five used for museum display, had been scrapped at Davis–Monthan AFB.
Convair B-36 Peacemaker