Google's ngram tool, provides frequency counts of the occurrences of words and phrases in books and other printed text across decades. Although it is not flawless, results obtained for ethnic epithets or racial slurs might mirror prevailing social attitudes. This illustration shows a count of the occurrence of two negative terms describing Chinese, Chinaman (in blue) and Chink (in red),from 1800-2000. The occurrence of 'chink' is relatively constant and lower than the occurrence of 'Chinaman,' which showed a sharp rise from 1840 to 1900 and large drop in occurrence from 1900 to about 1960. Whether these trends matched spoken use of these terms is a separate question, but one might think they would parallel each other.