These historic Senate Chamber maps are reproduced from the Congressional Directory. The desk numbers on the floor plans were used to quickly identify a senator's seating location in the U.S. Senate Chamber. They do not correspond to the numbers used today to identify individual desks.

Old Senate Chamber (1810-1859)
26th Congress1st Session1840
27th Congress1st Session1841
27th Congress2nd Session1841-1842
28th Congress2nd Session1845
29th Congress1st Session1845
30th Congress1st Session1848
30th Congress1st SessionJune 22, 1848
30th Congress2nd Session1849
31st Congress1st Session1850
31st Congress2nd Session1850
32nd Congress1st Session1852
32nd Congress1st SessionMay 28, 1853
32nd Congress2nd Session1853
33rd Congress1st Session1854
33rd Congress1st SessionJune 20, 1854
33rd Congress2nd Session1855
34th Congress1st Session1856
34th Congress1st Session1856
34th Congress3rd SessionDecember, 1856
35th Congress1st Session1858
35th Congress1st Session1858
Current Senate Chamber (1859-Present)
36th Congress1st Session1860
36th Congress1st Session1860
36th Congress2nd Session1861
37th Congress3rd Session1863
39th Congress2nd Session1866
39th Congress2nd Session1867
40th Congress1st Session1867
40th Congress2nd Session1867
40th Congress2nd Session1868
40th Congress3rd Session1869
40th Congress3rd Session1869
41st Congress1st Session1869
41st Congress1st Session1869
41st Congress1st Session1869
41st Congress2nd Session1869
41st Congress2nd Session1870
41st Congress3rd Session1870
41st Congress3rd Session1871
42nd Congress1st SessionMarch 25, 1871
42nd Congress2nd SessionJanuary 15, 1872
42nd Congress2nd SessionMay 20, 1872
42nd Congress3rd SessionDecember 14, 1872
42nd Congress3rd SessionFebruary 12, 1873
43rd Congress1st SessionFebruary 24, 1874
43rd Congress1st SessionJune 13, 1874
43rd Congress2nd SessionDecember 15, 1874
43rd Congress2nd SessionFebruary 1, 1875
44th Congress1st SessionDecember 20, 1875
44th Congress1st SessionJanuary 22, 1876
44th Congress1st SessionAugust 12, 1876
44th Congress2nd SessionDecember 13, 1876
44th Congress2nd SessionFebruary 1, 1877
45th Congress1st SessionOctober 18, 1877
45th Congress2nd SessionDecember 10, 1877
45th Congress2nd SessionFebruary 7, 1878
45th Congress2nd SessionJune 10, 1878
45th Congress3rd SessionDecember 9, 1878
45th Congress3rd SessionJanuary 29, 1879
46th Congress1st SessionApril 12, 1879
46th Congress2nd SessionDecember 6, 1879
46th Congress2nd SessionJanuary 29, 1880
46th Congress2nd SessionMay 20, 1880
46th Congress3rd SessionDecember 10, 1880
46th Congress3rd SessionJanuary 21, 1881
47th Congress1st SessionDecember 21, 1881
47th Congress1st SessionFebruary 1, 1882
47th Congress1st SessionJune 28, 1882
47th Congress2nd SessionDecember 11, 1882
47th Congress2nd SessionFebruary 3, 1883
48th Congress1st SessionDecember 24, 1883
48th Congress1st SessionFebruary 15, 1884
48th Congress1st SessionJune 30, 1884
48th Congress2nd SessionDecember 10, 1884
48th Congress2nd SessionFebruary 11, 1885
49th Congress1st SessionDecember 17, 1885
49th Congress1st SessionJanuary 16, 1886
49th Congress1st SessionMay 15, 1886
49th Congress2nd SessionDecember 11, 1886
49th Congress2nd SessionFebruary 5, 1887
50th Congress1st SessionDecember 3, 1887
50th Congress1st SessionJanuary 15, 1888
50th Congress1st SessionApril 15, 1888
50th Congress2nd SessionDecember 7, 1888
50th Congress2nd SessionJanuary 25, 1889
51st Congress1st SessionDecember 5, 1889
51st Congress1st SessionJanuary 25, 1890
51st Congress1st SessionMay 10, 1890
51st Congress2nd SessionDecember 3, 1890
51st Congress2nd SessionJanuary 15, 1891
52nd Congress1st SessionDecember 5, 1891
52nd Congress1st SessionJanuary 29, 1892
52nd Congress1st SessionMay 7, 1892
52nd Congress2nd SessionDecember 12, 1892
52nd Congress2nd SessionFebruary 10, 1893
53rd Congress1st SessionAugust 7, 1893
53rd Congress1st SessionOctober 10, 1893
53rd Congress2nd SessionDecember 1, 1893
53rd Congress2nd SessionFebruary 1, 1894
53rd Congress2nd SessionMay 1, 1894
53rd Congress3rd SessionDecember 1, 1894
53rd Congress3rd SessionFebruary 1, 1895
53rd CongressExtraordinary SessionApril 20, 1893
54th Congress1st SessionDecember 7, 1895
54th Congress1st SessionJanuary 15, 1896
54th Congress1st SessionApril 22, 1896
54th Congress2nd SessionDecember 12, 1896
54th Congress2nd SessionJanuary 22, 1897
55th CongressExtraordinary SessionMarch 12, 1897
55th CongressExtraordinary SessionJune 24, 1897
55th Congress2nd SessionDecember 13, 1897
55th Congress2nd SessionFebruary 21, 1898
55th Congress3rd SessionDecember 5, 1898
55th Congress3rd SessionJanuary 12, 1899
56th Congress1st SessionDecember 8, 1899
56th Congress1st SessionJanuary 10, 1900
56th Congress1st SessionApril 18, 1900
56th Congress2nd SessionNovember 27, 1900
56th Congress2nd SessionJanuary 8, 1901
57th Congress1st SessionDecember 5, 1901
57th Congress1st SessionJanuary 16, 1902
57th Congress1st SessionApril 11, 1902
57th Congress2nd SessionNovember 26, 1902
57th Congress2nd SessionJanuary 5, 1903
58th CongressSpecial SessionMarch 3, 1903
58th CongressExtraordinary SessionNovember 5, 1903
58th Congress2nd SessionDecember 4, 1903
58th Congress2nd SessionJanuary 21, 1904
58th Congress2nd SessionApril 1, 1904
58th Congress3rd SessionDecember 1, 1904
58th Congress3rd SessionJanuary 6, 1905
59th Congress1st SessionDecember 6, 1905
59th Congress1st SessionJanuary 10, 1906
59th Congress1st SessionApril 3, 1906
59th Congress2nd SessionNovember 30, 1906
59th Congress2nd SessionJanuary 9, 1907
60th Congress1st SessionDecember 4, 1907
60th Congress1st SessionJanuary 20, 1908
60th Congress1st SessionApril 15, 1908
60th Congress2nd SessionDecember 3, 1908
60th Congress2nd SessionJanuary 6, 1909
61st Congress1st SessionMarch 22, 1909
61st Congress2nd SessionDecember 3, 1909
61st Congress2nd SessionJanuary 17, 1910
61st Congress2nd SessionApril 7, 1910
61st Congress3rd SessionNovember 29, 1910
61st Congress3rd SessionJanuary 18, 1911
62nd Congress1st SessionMay, 1911
62nd Congress2nd SessionDecember, 1911
62nd Congress2nd SessionJanuary, 1912
62nd Congress2nd SessionApril, 1912
62nd Congress3rd SessionDecember, 1912
62nd Congress3rd SessionJanuary, 1913
63rd Congress1st SessionApril, 1913
63rd Congress2nd SessionDecember, 1913
63rd Congress2nd SessionFebruary, 1914
63rd Congress2nd SessionMay, 1914
63rd Congress3rd SessionDecember, 1914
63rd Congress3rd SessionJanuary, 1915
64th Congress1st SessionDecember, 1915
64th Congress1st SessionJanuary, 1916
64th Congress1st SessionMay, 1916
64th Congress2nd SessionDecember, 1916
64th Congress2nd SessionJanuary, 1917
65th Congress1st SessionApril, 1917
65th Congress2nd SessionDecember, 1917
65th Congress2nd SessionJanuary, 1918
65th Congress2nd SessionApril, 1918
65th Congress3rd SessionDecember, 1918
65th Congress3rd SessionJanuary, 1919
66th Congress1st SessionJuly, 1919
66th Congress2nd SessionDecember, 1919
66th Congress2nd SessionFebruary, 1920
66th Congress2nd SessionMay, 1920
66th Congress3rd SessionDecember, 1920
66th Congress3rd SessionJanuary, 1921
67th Congress1st SessionMay, 1921
67th Congress2nd SessionDecember, 1921
67th Congress2nd SessionFebruary, 1922
67th Congress2nd SessionJuly, 1922
67th Congress4th SessionDecember, 1922
67th Congress4th SessionJanuary, 1923
68th Congress1st SessionDecember, 1923
68th Congress1st SessionJanuary, 1924
68th Congress1st SessionMay, 1924
68th Congress2nd SessionDecember, 1924
68th Congress2nd SessionJanuary, 1925
69th Congress1st SessionDecember, 1925
69thCongress1st SessionJanuary, 1926
69th Congress2nd SessionDecember, 1926
69th Congress2nd SessionJanuary, 1927
70th Congress1st SessionDecember, 1927
70th Congress1st SessionJanuary, 1928
70th Congress2nd SessionDecember, 1928
70th Congress2nd SessionJanuary, 1929
71st Congress1st SessionMay, 1929
71st Congress2nd SessionDecember, 1929
71st Congress2nd SessionJanuary 18, 1930
71st Congress3rd SessionNovember 21, 1930
71st Congress3rd SessionJanuary 9, 1931
72nd Congress1st SessionNovember 27, 1931
72nd Congress1st SessionJanuary 15, 1932
72nd Congress2nd SessionNovember 23, 1932
72nd Congress2nd SessionJanuary 13, 1933
73rd Congress1st SessionJune 3, 1933
73rd Congress2nd SessionDecember 21, 1933
73rd Congress2nd SessionMay 4, 1934
74th Congress1st SessionDecember 20, 1934
74th Congress1st SessionMarch 21, 1935
74th Congress2nd SessionDecember 21, 1935
74th Congress2nd SessionApril 17, 1936
75th Congress1st SessionDecember 20, 1936
75th Congress1st SessionFebruary 18, 1937
75th Congress3rd SessionDecember 21, 1937
75th Congress3rd SessionMay 5, 1938
76th Congress1st SessionDecember 20, 1938
76th Congress1st SessionMarch 23, 1939
76th Congress3rd SessionDecember 19, 1939
76th Congress3rd SessionJune 6, 1940
77th Congress1st SessionApril 23, 1941
77th Congress1st SessionDecember 19, 1940
77th Congress2nd SessionDecember 19, 1941
77th Congress2nd SessionMay 26, 1942
78th Congress1st SessionDecember 21, 1942
78th Congress1st SessionMay 14, 1943
78th Congress2nd SessionDecember 21, 1943
78th Congress2nd SessionJune 2, 1944
79th Congress1st SessionAugust 14, 1945
79th Congress1st SessionFebruary 2, 1945
79th Congress2nd SessionJanuary 1, 1946
79th Congress2nd SessionJune 29, 1946
80th Congress1st SessionFebruary 14, 1947
80th Congress1st SessionJune 11, 1947
80th Congress2nd SessionDecember 13, 1947
80th Congress2nd SessionMay 19, 1948
81st Congress1st SessionFebruary 15, 1949
81st Congress2nd Session
82nd Congress1st Session
82nd Congress2nd Session
83rd Congress1st Session
83rd Congress2nd SessionJanuary 18, 1954
84th Congress1st SessionFebruary 14, 1955
84th Congress2nd Session
85th Congress2nd Session
85th Congress2nd Session
86th Congress1st Session
86th Congress2nd Session
87th Congress1st Session
88th Congress1st Session
88th Congress2nd Session
89th Congress1st Session
89th Congress2nd Session
90th Congress1st SessionFebruary 28, 1967
90th Congress2nd SessionDecember 15, 1967
91st Congress1st Session
91st Congress2nd SessionDecember 15, 1969
92nd Congress1st SessionMarch 10, 1971
92nd Congress2nd SessionDecember 3, 1971
93rd Congress2nd SessionDecember 22, 1973
94th Congress2nd Session
95th Congress1st SessionMarch 25, 1977
96th Congress1st SessionMarch 23, 1979
97th CongressApril 1, 1981
98th CongressMarch 31, 1983
99th CongressApril 5, 1985
100th CongressApril 15, 1987
101st CongressApril 18, 1989
102nd Congress
103rd Congress
104th Congress
105th Congress
106th Congress
107th Congress