All Aboard! 20th Century American Trains All Aboard! 20th Century American Trains In August 1999, the United States Postal Service issued a set of 33¢ postage stamps entitled All Aboard! 20th Century American Trains to ""pay tribute to American industry and design, and specifically to the heritage of our railroads."" Artist Ted Rose created five watercolor images depicting the following celebrated American named passenger trains from the 1930s and 1940s: Descriptive text regarding each of the trains was listed on the gummed side of each stamp. At the same time, the USPS offered for sale a booklet of "20 U.S. Postal Service Ready-To-Mail Stamped Postal Cards"
20th century in ichnology 1951 1952 1953 1954 1955 1957 1958 1959 1960 1962 1963 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 20th century in ichnology The 20th century in ichnology refers to advances made between the years 1900 and 1999 in the scientific study of trace fossils, the preserved record of the behavior and physiological processes of ancient life forms, especially fossil footprints. Significant fossil trackway discoveries began almost immediately after the start of the 20th