Edward Barry Mahon was born in the valley of the Ottawa, on Grand River, in the Dominion of Canada, in September 1834. He was the youngest son of Irish immigrants who were pioneers of that settlement. He was fortunate in having the advantage of excellent teachers, from whom he received a very thorough English education, and afterwards from private tutors, there being no college in the vicinity, who taught him Latin and French.
At an early age, however, he was thrown on his own resources, and at the age of sixteen or seventeen commenced teaching school, in which he developed an aptitude and proficiency far in advance of his years. His time, while out of the schoolroom, was devoted to study. Among other things, he exhibited an early love for the free institutions and laws of the United States, and was an advocate of annexation of the Canadas to that government, a proposition which at that time was often mooted.
Meanwhile, a brother of his, Timothy J. Mahon, who for some years had been a resident of the State of New York, on the first intelligence of the gold discoveries in California, in company with several others from New York, sailed from that city in 1849 and sought this western land of promise by way of Cape Horn. Edward B. Mahon left New York in the beginning of 1857, and his recollection of the very unlevel condition of the sea off Cape Hatteras and of the solemn protest which his inner man made against such actings and doings on the part of wind and waves, are still very vivid, if not inspiring. The change from the snows of New York to the tropical green of Jamaica was, if not a surprise, at least some recompense for all the wrongs inflicted on him by old Neptune.
The passage thence by way of the Panama Railroad and the Pacific mail steamer to San Francisco was uneventful. One of the small sloops then plying on the Bay of San Francisco served to convey him to San Rafael, where he arrived in April 1857. San Rafael then consisted of some half dozen houses, the principal of which was the former ranch house of Don Timoteo Murphy, afterwards owned by Timothy J. Mahon, brother of E. B. Mahon, who was then one of the solid men among the pioneers of Marin County, a position which, through its mutations of over thirty years, he has always maintained.
At the season in which Edward Mahon arrived, the valley of San Rafael was spread before him in all its native loveliness, the hills surrounding it, as well as the valley itself, clad in a deep green, the Bay of San Francisco on the one side, ranges of low hills with the lordly heights of Mount Tamalpais on the other, altogether presented, as it still does, a very beautiful landscape. It was a place for which nature had done much and art nothing. No fences met the eye in any direction, and nothing but the steepness of some points in the hills prevented the traveler from riding his horse to any point of the compass. The only road leading to or from the village was the one towards Petaluma, and the sight of any vehicle on that road was a rare occurrence. Horse-back was the universal means of travel and trails led in every direction, and, indeed, in proportion to the population there was at least as much traveling done then as now. Every man was a caballero, and the proprietor of from one to a dozen mustangs and sometimes half-breed American horses.
The native Spanish-California population predominated and the Spanish language was spoken by nearly everybody. Within six or eight months, with the aid of a stray volume of Ollendorf and a constant inquiry of the names of things, Edward Mahon acquired a sufficient stock of Spanish nouns and adjectives, with an occasional verb, to make himself understood.
The Murphy adobe ranch house was used as a Courthouse, and even at that early day cases involving the title to thousands of acres and hundreds of thousands of dollars, and embracing a wide range of civil and criminal jurisprudence, were argued and tried within the walls of that old adobe. Some of the most eminent lawyers in this State took part in these controversies. Judge E. W. McKinstry, now of the Supreme Court, was District Judge for the territory embracing Marin County, and James A. McDougall, afterwards United States Senator from California, James McM. Shafter, Treanor W. Park, Oscar L. Shafter, Judge Solomon Heydenfeldt, C. M. Bronson, afterwards Judge of the Supreme Court of Nevada, Solomon A. Sharp, W. H. Patterson, and many others occupied a great portion of their time and took a leading part in the litigation there conducted.
The first few years of Edward Mahon's time were spent in keeping store, for which he did not exhibit much aptitude, and having resolved to become a lawyer, under the instruction and advice of the Hon. C. M. Bronson, he purchased some books and commenced with a persistent determination that ordinary obstacles could not overcome to study the elements of law. He afterwards entered the law office of Cook, Bronson & Hittell, in San Francisco, as a law student. His studies here were interrupted by a severe attack of smallpox, which nearly cost him his life. As soon as he recovered, however, he returned to his studies at San Rafael with undiminished ardor, and in 1863 passed a very creditable examination before the Supreme Court of the State of California, at Sacramento, and obtained his license. He was afterwards admitted to practice in the United States District and Circuit courts.
He has always, since his arrival in this State, been identified with the County of Marin, and has been a resident of that county all of that time, except while pursuing his studies in San Francisco. He was elected County Treasurer of Marin County from 1865 to 1869.
He married his wife, Margaret, on October 8, 1867.
Mahon was the elected Marin County District Attorney from 1871 to 1873, which office he filled with unremitting care and unswerving fidelity.
As a lawyer, he is laborious, thorough and faithful, and displays a clear head and a logical mind; his practice, both in the District Court and Supreme Court, has been, considering the field open to him, both varied and eminently successful. Some of his briefs in the Supreme Court of this State won him high encomiums from the justices of that court for learning, soundness and ability. To the extent of his means he has been always ready to assist in any public improvement. In 1865, he assisted in the enterprise of building a turnpike road from San Rafael to connect with the steam ferry to San Francisco at San Quentin, and afterwards in the San Rafael and San Quentin Railroad between those points.
In 1871, the old adobe Courthouse was no longer adequate to the requirements of the county. Several ineffectual attempts had at different times been made to remove the county seat from San Rafael; a majority of the people however preferred its present location. To supply this want, and also to put an end to this agitation, it was finally resolved to build a new Courthouse; accordingly, E. B. Mahon who was then District Attorney, prepared a bill which he, seconded by the Hon. J. B. Rice, then the representative for Marin County in the Assembly, got passed by the Legislature in January 1872, providing for the building of a new Courthouse. He had the pleasure of seeing the present solid and substantial Courthouse erected in San Rafael within the same year, a structure, which, for beauty of design, durability, and cheapness in the cost of construction, compares favorably with any Courthouse in the State of equal cost.
After serving as Marin County District Attorney, Mahon served for several years as Judge of the Marin County Superior Court.
He died on March 21, 1907, in San Rafael, at age 74, from an attack of paralysis.