Question: Which year did the agency working on USRA 2-8-8-2 end?

full_context: Document 1: USRA 0-6-0: The USRA 0-6-0 was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. This was the standard light switcher of the USRA types, and was of 0-6-0 wheel arrangement in the Whyte notation, or "C" in UIC classification.
Document 2: USRA Heavy Mountain: The USRA Heavy Mountain was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. This was the standard light freight locomotive of the USRA types, and was of 4-8-2 wheel arrangement in the Whyte notation, or 2′D1′ in UIC classification.
Document 3: USRA 0-8-0: The USRA 0-8-0 was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. This was the standard heavy switcher of the USRA types, and was of 0-8-0 wheel arrangement in the Whyte notation, or "D" in UIC classification.
Document 4: USRA Light Mountain: The USRA Light Mountain was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. This was the standard light freight locomotive of the USRA types, and was of 4-8-2 wheel arrangement in the Whyte notation, or 2′D1′ in UIC classification.
Document 5: USRA Light Pacific: The USRA Light Pacific was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. This was the standard light passenger locomotive of the USRA types, and was 4-6-2 wheel arrangement in the Whyte notation, or 2′C1′ in UIC classification.
Document 6: BR Standard Class 8: The BR Standard Class 8 was a class of 4-6-2 "Pacific" steam locomotive designed by Robert Riddles for use by British Railways. Only the prototype was constructed, which was named "Duke of Gloucester". Constructed at Crewe Works in 1954, the "Duke", as it is popularly known, was a replacement for the destroyed LMS Princess Royal Class locomotive number 46202 "Princess Anne", which was involved in the Harrow and Wealdstone rail disaster of 1952.
Document 7: USRA Heavy Santa Fe: The USRA Heavy Santa Fe was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. These locomotives were of 2-10-2 wheel arrangement in the Whyte notation, or 1′E1′ in UIC classification; this arrangement was commonly named "Santa Fe" in the United States. At the time, the Santa Fe was the largest non-articulated type in common use, primarily in slow drag freight duty in ore or coal service.
Document 8: USRA Heavy Mikado: The USRA Heavy Mikado was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration (USRA), the nationalized railroad system in the United States during World War I. These locomotives were of 2-8-2 wheel arrangement in the Whyte notation, or 1′D1′ in UIC classification. A total of 233 locomotives were built to this plan for the USRA; postwar, it became a "de facto" standard design, which was built to the total of 957 locomotives including the USRA originals and all subsequent copies.
Document 9: USRA Light Santa Fe: The USRA Light Santa Fe was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. These locomotives were of 2-10-2 wheel arrangement in the Whyte notation, or 1′E1′ in UIC classification; this arrangement was commonly named "Santa Fe" in the United States. At the time, the Santa Fe was the largest non-articulated type in common use, primarily in slow drag freight duty in ore or coal service.
Document 10: USRA Heavy Pacific: The USRA Heavy Pacific was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. This was the standard heavy passenger locomotive of the USRA types, and was 4-6-2 wheel arrangement in the Whyte notation, or 2′C1′ in UIC classification.
Document 11: USRA Light Mikado: The USRA Light Mikado was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. This was the standard light freight locomotive of the USRA types, and was of 2-8-2 wheel arrangement in the Whyte notation, or 1′D1′ in UIC classification.
Document 12: USRA 2-8-8-2: The USRA 2-8-8-2 was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. These locomotives were of 2-8-8-2 wheel arrangement in the Whyte notation, or (1'D)'D1' in UIC classification. A total of 106 locomotives were built to this plan for the USRA; postwar, it became a de facto standard design.
Document 13: United States Railroad Administration: The United States Railroad Administration (USRA) was the name of the nationalized railroad system of the United States between December 28, 1917, and March 1st, 1920. It was possibly the largest American experiment with nationalization, and was undertaken against a background of war emergency.
Document 14: Pacific 231: The popular interpretation of the piece is that it depicts a steam locomotive, an interpretation that is supported by the title of the piece alongside film versions. Honegger, however, insisted that he wrote it as an exercise in building momentum while the tempo of the piece slows. He originally titled it Mouvement Symphonique, only giving it the name Pacific 231, a class of steam locomotive designated in Whyte notation as a 4-6-2, with four pilot wheels, six driving wheels, and two trailing wheels (the French, who count axles rather than wheels when describing locomotives, call this arrangement 2-3-1) after it was finished.
Document 15: USRA 2-6-6-2: The USRA 2-6-6-2 was a standardized design of 2-6-6-2 Mallet locomotives developed by the United States Railroad Administration during World War I.
ground_truth: 1920
sub_queries: Who worked on USRA 2-8-8-2? Answer: United States Railroad Administration
Which year did United States Railroad Administration end? Answer: 1920