She was built in 1889 by Delaware River Iron Ship Building and Engine Works, Chester, Pennsylvania, as merchant ship Yumuri, purchased for use in the Spanish–American War on 19 April 1898 and converted to an auxiliary cruiser at New York Navy Yard, then commissioned on 25 April 1898, Commander A. S. Snow in command; and joined the North Patrol Squadron.

On 26 July 1898, off the Dry Tortugas, she seized a Spanish tug with two vessels in tow, each with a quarantine flag hoisted.

They were given medical assistance, provisioned, and kept in port until 3 August when a prize crew was put aboard the tug to sail her to New York.

Badger remained on the east coast until 26 December 1898 when she sailed to the Pacific, arriving at San Francisco 15 April 1899.

Following her return to Mare Island Navy Yard on 14 August 1899, she cruised along the Pacific coast until 6 October 1899 with the Oregon and California Naval Militia.