Dennis J. Oliver (1823-1886) was born in Galway, Ireland. He emigrated to NYC in 1840 at the age of 17 and there eventually met and at the age of 25 married Bridget McGlynn (1825-1870) on May 11, 1848. For awhile in NYC he was in partnership with John A. McGlynn [from Chart II, not clear what John's relationship to Bridget was] in the paint business. Eight months later (January 1849), after receiving news of the gold discovery in California, Dennis with John McGlynn and William F. White sailed for San Francisco, arriving there 156 days later. His pregnant wife stayed behind. He immediately reestablished his paint business in San Francisco, and despite a series of fires that destroyed at least two of his principal buildings, he prospered.
In 1854 Oliver began keeping a diary—the first entry is November 9th—which eventually grew to 14 volumes, now kept at the California Historical Society in San Francisco. The first volume contains some information on the land he bought in what is now Menlo Park.
Notes from vol. 1 of Denis Oliver's diary
Conclusions from the notes.
Photocopy of entry of February 6, 1855, in which Denis states why he named his ranch Menlo Park.
Chart I - Family tree for Dennis Oliver
Chart II - Family tree for Bridget McGlynn
4/19/1886 San Francisco Reports - Obituary of Denis J. Oliver
4/24/1886 Redwood City Times Gazette - Obituary of Denis J. Oliver
For additional information see Denis J. Oliver Diaries in research blog by Jake Fletcher, and for more detail see the finding aids for the Oliver Diaries (MS 3577) prepared by the California Historical Society
Notes from vol. 1 of Denis Oliver's Diaries:
In 1854 Oliver began keeping a diary—the first entry is November 9th—which eventually grew to 14 volumes, now kept at the California History Society in San Francisco. The first volume contains some information on the land he bought in what is now Menlo Park. In the following notes from vol. I, the 3rd person is used when not a direct quote. Notes from other than the diary are in brackets. Notes of special interest are highlighted.
11.1854. Reports death of brother-in-law Peter B. McGlynn (1827-1854) [see Chart II].
11.25.1854. “I heard yesterday that there was a hundred acres of the Ranch owned McGlynn & self bured [sic] whlich make it bad for our cattle.”
12.9.1854. “I went down to the Ranch last Sunday and left the following morning. The grass was considerably burndt the cattle did not look as good as I expected to see. My brother John came down with me….”
12.12.1854. Played “Fox & Geese” with friends. Reminded him of childhood.
“Hohn Neugent Editor of the Herold and a Townsman of mine (all the way from Galway….”
1.24.1855. “This day 6 years ago  I sailed from New York for California….” Arrived in SF after 156 days, on June 30th. Came ashore on July 6th with partners William F. White and John ? McGlynn [No John McGlynn in Chart II]. Following a miserable December, he dissolved the partnership and determined to return to East. But later he decided to stay, took partner Charles Delbeechio [sp?]. Fire destroyed the store, it was rebuilt, partnership dissolved 6.22.1850. Bridget sent message that child Peter had died. Bridget arrived 12.11.1850 accompanied by her brother Daniel [ca 1830-1876 on Chart II]. Took Daniel as partner. On May 4,1851, a conflagration, great loss, soon after a new store built, but in a few months dissolved the partnership. Sent for brother [John] and sister [Sarah?], but latter remained in NYC and got married. John was an employee for awhile. 8.20.1853 John P. Buckley, “a youth in Galway,” was a partner for awhile.
2.6.1855. “On last Friday the 2nd inst Dan stopped at the store for me with his buggy to accompany him to our Ranch (Menlo Park) so called by me after Menlo a lovely place on the banks of Lough Corrib two miles from the Town of Galway the ancient Town of my nativity and of my ancestors. Menlo is the place where the Inhabitants of the Town and surrounding country go to enjoy themselves the first three Sundays in May. The Ameture [sic] & Military bands together with Fidlers & Pipers play delightful music on these occasions, whilest the crowd promenades the shady groves, the young and lively dance on the daisey [sic] clad fields, and lovers seek more retirement in adjacent bowers. The Youngsters can be seen on the summits of lofty trees robbing birds nests, every countenance beams with joy and gladdiness [sic], numerous tents and fruit stands are strewed in various parts of the demesne. In fact every person who can raise money enough to pay their passage will go a haying to Menlo.
“We got down to the Ranch about ten oclock, it was four when we left San Francisco. We took supper at the twelve mile house it was a lovely moonlight night. There are ten persons employed by us on the Ranch including the wife of one of the men. The were all asleep two got up to rub down the horses. Mrs McDermott also got up and made a cup of tea for us. Next morning we arose at 5 o’clock. I was much pleased at how things were getting on. The new gate pleased me very much. Mr Hamilton the superintendent had the men clearing an [sic] plowing the land. The carpenter was altering and repairing the house. We rode over to I.C. Woods farm (opposite) to see the improvements and how things are conducted as we are both ignorant of farming and we require considerable improvements made. We also rode ten miles to three different saw mills amongst the hills in the red woods for the purpose of ordering lumber to build a framed house and yard one hundred and twenty feet square. Dan bought on the way, a turkeycock and carried him on front of the saddle. When we returned in the evening. I felt very much fatigued [sic] from all I rode. We lost the road by a man giving us a bad short cut, but we found before we reached the house it was about five miles of a round. Mr Lewis who is surveying for a rail road from San Jose to San Francisco is encamped with his assistants on our land called in and we entertained him as much [?] as circumstances would permit. I felt so sleepy after my day riding that I had to go to bed after supper.
“The following morning Dan drove the large wagon drawn by four mules containing six of the men and Mrs McDermott to Church [Dennis Martin’s church in Searsville was the only church in what became (after 1856) San Mateo County] which is Five miles distant, when we got there we found the church empty as the Revd Clergyman from San Jose did not get down as he generally does the first Sunday in every month. When we returned to the house Lewis showed us a map of the Rail Road it runs through our land ¾ of mile from the County road on the south end and ¼ of a mile on the north end.
“We started for home at about one o’clock and got in at Five after Tea Dan, Mr Morgan & Callahan went to vespers with me. After vespers we took a walk. While I [was] absent in the country my dear wife suffered considerable pain from a gumboil.”
2.22.1855. There is a mortgage on the MP Ranch for $10,000, which was on it when “we” purchased it.
2.23.1855. Bank failures: Adams, Wells Fargo, Robinson, Wright.
9.12.1855. Inspected bridge at San Francisquito.
9.16.1855. This is the 15th anniversary of “my” leaving Galway [so 1840 when about 17].
9.19.1855. Mr Johnson has the mortgage ($10,000) on 500 acres of the MP Ranch. Being short of cash at the moment, decided to leave him the land, but keep the 159 acres that is not mortgaged.
9.22.1855. Oliver regrets giving up the 500 acres since the sheriff was able to sell it for $11,000.
12.21.1855. Sold W.F. White 17 head of cattle from the Ranch at $65 each.
12.22.1855. Sold White 50 cowes [sic] at $45 each.
Conclusions from the notes from vol. 1 of Denis Oliver's diaries:
1. The total amount of land purchased by Oliver and McGlynn (sometime before 1854, but what year?) was 659 acres (640 acres = 1 sq. mi.). A previous owner (Johnson?) held a mortgage on 500 acres of this land. The 500 acres were given up to the mortgager in 1855. Maybe later volumes of the diary tell what happened to the remainder.
2. Oliver named the ranch Menlo Park after Menlo, Ireland, a place which at the time was near, but not part of, the Town of Galway.
3. Based on Oliver's comment recorded on February 6, 1855, construction of the gate to the ranch (which was on County Road, now El Camino Real) probably began in 1854 but was not completed until 1855. There’s no evidence in Oliver's diary that it was inspired by the Menlo Castle gate, although the similarities are striking. There is also no statement of what was painted on the gate (names, dates, etc.).
4. In 1855 Oliver and McGlynn had a crude structure or house (not a frame house) on their Ranch for their employees (10). At least for the first few years neither Oliver nor McGlynn lived there. They may soon after have built a frame house or houses.