The first use in English is from 1854, nine years before Sombart's birth, with use (as "private capitalism") in teaching and disputing about economy in USA sinc

The first use in English is from 1854, nine years before Sombart's birth, with use (as "private capitalism") in teaching and disputing about economy in USA since 1863 by Carl Adolph Douai. "Capitalism" in the modern sense is apparently attributed to Louis Blanc (1850) and Pierre-Joseph Proudhon (1861, explicitly calls out owners of capital being dissociated from actually working it). As a word with way less scientific rigour than some of the stricter mathematical sciences, the exact way of using it also has considerable variation due to differences in languages. Marx used "capital" and "capitalist", which are older terms. "Capitalism" as a term evolved from the same use that Marx learnt from, with earliest uses of "capitalists" being associated with 1633.