For those of you who enjoy researching the companies you collect, sooner or later you will need to look at Poor's Manuals of Railroads.

Henry Varnum Poor was an early writer on railroads and corporate investments. Starting in 1868, he issued an annual volume specifically dedicated to railroads. The actual title of the volume changed over time, but the layout and type of content stayed remakably uniform.

Today, the early editions are pricey, especially if they are in good condition. Some people like to buy distressed volumes and have them rebound.

At long last, some of the volumes are becoming available online. The largest collection can be found at "Internet Archive". Two additional volumes can be found at Google Books. (Thanks to Pete Angelos for bringing these to my attention a couple months ago.)

• 1868 (vol 1, at Google Books)
• 1874 (vol 7, at Internet Archive)
• 1876 (vol 9, at Internet Archive)
• 1877 (vol 10, at Internet Archive)
• 1878 (vol 11, at Internet Archive)
• 1880 (vol 13, at Internet Archive)
• 1881 (vol 14, at Internet Archive)
• 1882 (vol 15, at Internet Archive)
• 1884 (vol 17, at Internet Archive)
• 1885 (vol 18, at Internet Archive)
• 1887 (vol 20, at Internet Archive)
• 1891 (vol 24, at Internet Archive)
• 1892 (vol 25, at Internet Archive)
• 1893 (vol 26, at Internet Archive)
• 1894 (vol 27, at Internet Archive)
• 1895 (vol 28, at Internet Archive)
• 1896 (vol 29, at Internet Archive)
• 1897 (vol 30, at Internet Archive)
• 1898 (vol 31, at Internet Archive)
• 1899 (vol 32, at Internet Archive)
• 1901 (vol 34, at Internet Archive)
• 1902 (vol 35, at Internet Archive)
• 1903 (vol 36, at Internet Archive)
• 1917 (at Google Books)