Map produced in 1970.
Source: The National Atlas of the United States of America (1970)

Map from page 76 "The Public Schools Historical Atlas" by Charles Colbeck. Longmans, Green; New York; London; Bombay. 1905.
Source: The Public Schools Historical Atlas by Charles Colbeck. Longmans, Green; New York; London; Bombay. 1905

Map from page 34 of "The Public Schools Historical Atlas" by Charles Colbeck. Longmans, Green; New York; London; Bombay. 1905.
Source: The Public Schools Historical Atlas by Charles Colbeck. Longmans, Green; New York; London; Bombay. 1905

European languages in the World 1914
Source: The Historical Atlas by William R. Shepherd, 1923.

World map 1860
Source: Otto Petri

World map, Nova Orbis Tabula 1662
Source: Frederik de Wit

Progress of the war, with detailed map of Tsingtao.
Source: Shou Hisou

Historic map of the world 1628
Source: Robert Vaughan

World historic map 1581
Source: Nicola van Sype

World Map with Mercator Projection 1820
Source: Abraham Rees