When was the Lincoln Memorial built?
1922
1931
1922
1931
1922
1931
1922
1931
1921
1922
1931
1921
1922
1931
1921
1922
1931
1921
1922
1931
1921
1922
1915
1931
1921
1922
1915
1931
1921
1922
1915
1923
1931
1921
1922
1915
1923
1932
1931
1921
1922
1915
1923
1932
1924
1931
1921
1922
1915
1923
1932
1922.
1939
1924
1931
1921
1922
1915
1923
1932
1909
1939
1924
1922.
1931
1913
1914
1921
1922
1915
1923
1932
1921.
1909
1939
1924
1914
1931
1921
1922
1915
1923
1932
1927
1922.
1909
1939
1913
1914
1924
1921.
1931
1921
1922
1915
1923
1914
1932
1909
1939
1924
1927
1922.
1931
1913
1914
1921
1922
1915
1926
1923
1932
1921.
1919
1939
1924
1914
1909
1931
1921
1922
1915
1919
1920
1923
1932
1927
1922.
1939
1913
1914
1926
1924
1921.
1931
1919
1920
1921
1922
1915
1923
1914
1932
1909
1922,
1919
1920
1924
1927
1922.
1939
1907
1913
1914
1921
1915
1926
1923
1932
1921.
1919
1920
1922,
1924
1914
1909
1921
1915
1919
1920
1923
1932
1927
1922.
1939
1907
1913
1914
1926
1924
1922,
1921.
1919
1920
1921
1915
1923
1914
1932
1909
1913
1919
1920
1927
1922.
1922,
1939
1907
1914
1915
1926