He briefly moved to New Orleans for two years when he was seventeen, and then returned to Poughkeepsie to study law, being admitted to the bar by the Supreme Court of New York in 1859.

On petition from local businessmen, the Reconstruction-era governor of Texas, Andrew Jackson Hamilton, commissioned him as mayor of the city in 1865, which was then struggling with martial law, a demoralized population and a bankrupt treasury.

[2] After he left office, he helped establish the first Republican newspaper in Texas, the San Antonio Express, and served as editor for eight months.

In 1892 he drew up articles to incorporate a women's club, and in 1894 he helped establish a chapter of the Southern California Society of the Sons of the American Revolution.

[2][1] While in San Diego, Cleveland became friends with Oliver Sanford, a local surveyor for the railroad who enjoyed collecting and identifying beetles.

Impressed by the diversity of plants, animals, and habitats in the region, the two men decided to form a society to serve local natural history.

It initially was a club for nature hobbyists, with the society holding weekly meetings, they soon established a scientific library, and began to handle donations of plant, animal, and fossil collections.

Cleveland made collections of the local flora, becoming the first to produce a systematic study of the plants of the San Diego area after the 1850 boundary survey.

He also corresponded with numerous other scientists, European and American, submitting many new taxa of plants and animals, including a genus of fish named in his honor.

His particular interest was in ferns, and his plant collection that he gifted formed the initial bulk of the San Diego Society of Natural History's herbarium.

[7] Preoccupied with community and scientific service, Cleveland had found little time for marriage, until he finally married the widow Marion South Webb on July 22, 1921.