Green’s Dictionary of Slang

1. conceited.

1848		J.R. Lowell Biglow Papers (1880) 1: He see a cruetin Sarjunt a struttin round as popler as a hen with 1 chicking.
1862		J.R. Lowell Biglow Papers 2nd series (1880) 61: It made us feel ez pop’lar ez a hen doos with one chicken.

2. good, e.g. a popular pie.

1884

Sat. Rev. (London) 8 Nov. 590/2: New York restaurant [...] ‘I don’t call this very popular pie’. They have come [...] to take popular quite gravely and sincerely as a synonym for good .