The sub-division of the land included in Cottesloe Suburban Lots 98 and 101 led to the creation of Mann Street in 1903.

Cottesloe Suburban Lot 98 (west side house numbers 13 to 25, east side 16 to 28) was originally issued to James Orchard Oxley and Joseph Hope in 1892 as tenants in common.

The obituary of James Orchard Oxley (1860/61-1925) which was published in the Sunday Times read:
Mr James O Oxley who passed away a few days ago at his Darlington residence. In his early days he was a well known figure on the goldfields and also in London where he assisted in the floatation of a number of mining companies. In more recent years he was engaged in survey, and carried out numerous works for the Government._{The Sunday Times Perth WA, 23rd August 1925}

Joseph Hope (1858-1934) was born in Fremantle, the son of Samuel Hope and Mary Ann Button. In 1883 he married Annie Ledsam Throssell (1863-1916) in Northam. He was a lithographer at the Government Print Office and later became Chief Draftsman at the Lands Department (Perth). He was educated at Perth Boy's School in St George's Terrace.

On 9 December 1891 Joseph Hope's interest in Lot 98 was transferred to James Orchard Oxley.

In 1895, Lot 98 was transferred to Fredrick Gatwood (1851 - 31 July 1894), a publican. In 1894 Fredrick Gatwood died intestate and his widow Mary Ann (Annie) Gatwood nee Burness (22 July 1862 - 4 January 1932) was appointed Administrator of his Estate. Annie Gatwood married George Henriques (1866 - ?) in 1897. In 13 June 1902 a half share of Lot 98 was transferred to George Fredrick Moore.

In 1902, Annie Henriques was replaced as Administrator by Sydney Hurst Mann. In 1898 he was appointed receiver to the Gatwood Estate a fidelity guarantee being taken out in the Colonial Mutual Insurance Company for £400.

Three days later on the 16th June 1902, the remaining half share of Lot 98 was also transferred to George Fredrick Moore.

Sydney Hurst Mann (15 July 1868 - 10 August 1905) was born in Glebe, New South Wales. S H Mann was one of the auditors for the Perth City Council. He was thought to have a lucrative accountancy business. He was interested in all forms of 'manly' sport especially rowing. He was Patron of the Henley Park Cricket Club. In 1905 he was involved in a dispute over the amount of commission he was entitled to charge the Gatwood estate. It seems that having to repay some of the money was too much for him and he shot himself in the bush in South Perth. His body was found by some children looking for a missing cow.

Cottesloe Suburban Lot 101 (west side house numbers 1 to 11, east side 2 to 14) originally belonged to James William Hope (1851-1918). The certificate of title was dated the twenty second of December 1891. He purchased the 5 acres 32 perches in a government land sale for £72 16s. _{The Western Mail, 11 July 1891, page 38}

James Hope was born in Wales and qualified as a medical practitioner in England in 1874. In that year he took up an appointment as District Medical Officer at York, Western Australia. In 1978 he married Helena Aurora Monger. At York he undertook some successful pastoral enterprises. He organised gold prospecting parties, which were also largely successful. From 1879 he held various military postings (concurrently with his other medical roles) and eventually attained the rank of Surgeon-Major. In 1882 he was appointed Medical Officer to the Fremantle Gaol and to the Convict Establishment at Rottnest, Port Doctor and Medical Officer to the Town of Fremantle. He was involved with the foundation of Fremantle Public Hospital. In 1902 he was elected President of the British Medical Association (Western Australian Branch). In 1911 the Medical Health Department was formed and he became the first Commissioner of Public Health. After resigning from the Public Health Department in 1915, he joined the Red Cross Society in England. He was posted to a base hospital in Boulogne (France), where he died of epidemic influenza a week before the Armistice was declared in November 1918.

In 1897 lot 101 was transferred to James Grave and Annie Gatwood as tenants in common.

James Grave (1849-1906) was the owner of the Osborne Hotel (later to become Loreto Convent). Areas close to this hotel were supplied with water from a freshwater bore that was in the grounds. The original controller of the bore had been W D Moore. In 1903 the government purchased the bore and associated pumping station and concrete tank in Congdon Street. James Grave was an early pioneer in the goldfields in Western Australia where he spent a large fortune attempting to develop ventures at Southern Cross, Golden Valley, Parker's Range and the Kimberley, later becoming involved in suburban land speculation and commercial activities including the Federal Furniture Factory.

James Grave sold his share of lot 101 to George Fredrick Moore in 1899. Annie Henriques's share was transferred to Sydney Hurst Mann in 1900. It was subsequently transferred to George Fredrick Moore in 1902.

Thus in 1902, George Frederick Moore (1865-1935) become the owner of over ten acres of land being the combination of lots 98 and 101.

George Frederick Moore was born Fremantle in 1865. In 1908 he married Ethel Hamersley. He purchased the Fremantle warehouse from his father of WD Moore & Co (Henry Street) which specialised in supplying merchandise and hardware to the north-west He was also a director of Norwich Union Insurance Company and also of the Fremantle Gas and Coke Company (founded 1895).

At noon on the 15th day of January 1903 a strip of land, "Mann Street", which runs from Grant Street to Eric Street was transferred in to the name of His Majesty King Edward VII. Blocks in the sub division of lots 98 and 101 become the houses facing onto to Mann Street. The Rights of Way were also created.

Mann Street could have been named after Sydney Hurst Mann. The author Ruth Marchant James suggests however that it could be named after Edward Alexander Mann (1874-1951). E. A. Mann was a resident of Claremont at the time and a chemist. He later became a politician and a controversial ABC broadcaster. He believed that all members of a democracy should exercise their right to vote and steered the (Commonwealth) Electoral Act (1924) through parliament which established compulsory voting.