Mechanism modeling is essential for the formulation of efficient design procedures as well as for analysis purposes in catalogs and classifications. Symbolic notation is the basis of the mathematical formulation that has been proposed since the beginning of the nineteenth century during which several solutions were proposed. Those early symbolic notations of mechanisms, mainly due to Babbage, Reuleaux, and Masi, are presented and discussed in this work with the aim of tracing a historical background that is also fundamental for modern developments. Modern symbolic notations have evolved from these early attempts and are still being developed for design and analysis algorithms increasingly suited to broader classifications and increasingly efficient analysis and synthesis procedures.