In 1829, he moved to Cincinnati, Ohio and served as a deputy sheriff and as a county recorder.

[1] Either in late 1849 or early 1850, he began working as a recorder clerk in the administration of mayor John W. Geary until August of that year, when he moved to Portland, Oregon.

[4] In 1852, Bonnell was elected as Portland's second mayor, succeeding Hugh O'Bryant.

[5] He served as mayor for six months, then resigned to take a long business trip.

In 1856, after his lumber mill burned down, Bonnell moved permanently to San Francisco.