Oscar Newburg, a Jewish emigrant to America from Prussia, was born in Stettin, Germany, on December 1, 1848, the son of Moses and Rahel Newburg. He came to America in 1863 at the age of 15 with other Jewish emigrants and settled in San Bernardino.
Many historical writing spell his name “Newberg,” though he always spelled it “Newburg.”
In San Bernardino, Newburg obtained employment as a clerk in a store and steadily began to make himself a respected and prosperous citizen. He was naturalized on July 19, 1869 in San Bernardino.
An event which assisted him was his marriage on July 7, 1878 to 19-year-old Sarah Jacobs, the daughter of a wealthy merchant and banker, Lewis  Jacobs, also a native of Prussia. Oscar and Sarah Newburg had one son, Mervin Jacobs Newburg, born on April 14, 1881, and a daughter, Lucille, born on June 19, 1887.
Newburg became the proprietor of a successful grain and shipping business. He later engaged in general merchandizing and became of one of the most prominent businessmen in San Bernardino. He instituted the Independent Order of Odd Fellows Token Lodge #290 in San Bernardino on March 27, 1880, and became the Grand Master. In 1882, Newburg and Dan Rathbun, a Second District county supervisor in 1859 and 1860, established the “Caley-Caro” Sawmill in a stand of swarthout timber at  Cedar Springs on the forks of the Mojave River in Summit Valley. It became known as the Summit Shingle Mill. The products were hauled out via Horsethief Canyon and down Cajon Pass or out to the desert towns. In October 1887, Mr. Newburg was elected vice-president of the newly-organized Board of Trade which was formed to aid in improving the image of San Bernardino, securing public improvements and attracting new settlers and capital investments.  In July 1887, Newburg, W.N Crandall, W.J. Curtis and N.B. Garner, who was county supervisor from 1883 to 1889, became a link in the valley railroad network. The new Redlands motor line brought its first train to Redlands on May 17, 1888. Regular two-hourly service began on June 4 and was a most important factor in the growth of that community. Mr. Newburg became the president of the San Bernardino and Redlands Railroad Company.
San Bernardino, reincorporated as a city on August 10, 1886, was then governed by a board of trustees or city council. Oscar Newburg was elected to this board for a term of four years in 1887. He served as its president, the equivalent of mayor from April 6, 1889 until January 21, 1891, at which time he tendered his resignation. He was elected to the San Bernardino County Board of Supervisors, representing the Fourth Supervisorial District, in 1894 and served from January 7, 1895 to January 2, 1899. He succeeded Jacob N. Victor and was succeeded by Theodore F. White.
Mr. Newburg became affiliated with the Bank of San Bernardino, the first bank in the city, which had been co-founded by his father-in-law, Lewis Jacobs and the brothers, Julius and Caesar Meyerstein in 1874. Mr. Jacobs became the manager in 1875 and after his death in 1900, Mr. Newburg became the manager. Following the Panic of 1907, the bank, along with many others around the country, failed. Newburg sold his properties in and around San Bernardino during 1909 and 1910 and moved to San Francisco. His is listed in the 1911 San Francisco city director as residing in the Granada Hotel, corner of Sutter and Hyde Streets, occupation: “Capitalist.” At the time of his death on July 9, 1929, at the age of nearly 81, the Newburgs resided at the Warrington Apartments, San Francisco.
Mr. Newburg was survived by his wife, Sarah; a son, Mervin of Manhattan Beach, California; a daughter, Lucille (Mrs. Korn, wife of Felix Korn of the Zellerbach Paper Company); and a sister, Miss Jennie Newburg. Mr. and Mrs. Newburg had no grandchildren. At the time of his death, Mr. Newburg still owned over one-fourth of the frontage on both sides of Third Street between “F” and “G” streets in San Bernardino.