In June 1886 he was elected to the New South Wales Legislative Assembly to succeed the former NSW premier Sir John Robertson KCMG as one of the members for Mudgee.

William Chandos Wall was a 'liberal' Protectionist member in the NSW Parliaments from the 12th to the 16th inclusive (under the Jennings, Parkes, Dibbs and Reid Governments).

A by-election was then held on 14 October 1895 and although Fitzpatrick was again returned, it appeared that Wall was correct in his assertion that the original count was irregular.

Wall also stood in the 1902 by-election for the seat of Inverell as an Independent Federalist obtaining 26.5% of the vote, but finished third behind the Labor Party candidate, George Alfred Jones, who won 37.7%.

[4] The (pro-Protectionist) Bulletin Weekly of 12 October 1916 said: "Though unheard of in politics these days W. C. Wall once loomed large on the New South Wales horizon.

This claim (it actually was about sending his old boots up to Wollar) was ascribed to Wall as part of what appeared to be a ‘dirty tricks’ campaign around the 1895 election.

He appears to have been a knowledgeable geologist and over his long career prospected for or mined: antimony (at Moolarben – 20 Km NE of Crossroads, Mudgee), gold, iron at Cooyal and Tallawang, tin and tungsten (Ardlethan and Yalgogrin, NSW), coal and kerosene shale (Megalong Valley), limestone, dolomite and gypsum (at Wall's Mt.

Wall's Pass from the adjacent Cedar Valley up the eastern escarpment to the Narrow Neck Plateau is named after him.

As a result of his survey work, in October 1888 he took out Mining Permits in the Megalong Valley, NSW around Narrow Neck and Ruined Castle.

Between 1892 and 1895 (the year he was defeated in the Rylstone Election) he took out further mining leases at Hargraves (with George Ensor), at Windeyer (with Robert Victor Leffley) and alone at Peak Hill (130 Km west of Mudgee).

[13] Wall was an activist for sound forestry management and was well known for his knowledge of geology and as a champion for mining and miners when he served in parliament.

After his parliamentary service, his Megalong Valley enterprise and his discharge from bankruptcy on 19 Nov 1901, Wall's activity switched back to the Mudgee area.

[15] (However in 1924[16] and again in the 1940s, shale was being carted from the Barigan deposits to the rail head at Lue – 25 km south east of Mudgee – on the second occasion, when additional oil was needed during the Second World War.)

By 1911, Wall was operating gypsum (Calcium sulphate), dolomite (Calcium-Magnesium carbonate) and limestone (Calcium carbonate) quarries on Dolomite Road at Mount Knowles near Mudgee (possibly with his brothers Ignatius and Damian) and ran a private tramway to move the quarried stone to connect with the main railway from Mudgee to the Blue Mountains at Wall's Siding, Mount Knowles.

"Messrs. G. & C. Hoskins being supplied by Messrs. Curlewis, also of Wall's Siding, the dolomite in this instance being calcined in a cupola furnace before railing to Lithgow".

In October 1912, a William Wall is listed as holding a 4 acre mining lease at Yambulla (south of Cooma, NSW).

These rented offices were burnt down along with a few shops and the Bank of NSW on Christmas morning 1914[19] It must have been a significant set back at 69 to have lost all his professional equipment in this fire.

The 1917 Sands Country Alphabetical Directory lists W. C. Wall as a Mining Agent at Ardlethan, NSW (80 km east of Griffith).

When he was 12, the Mechanics Institute Library was located in a property at 3 Short Street Mudgee belonging to his uncle, Thomas Spicer.

Mary was a strong resourceful woman and was raised on cattle stations on the anabranch of the Macintyre River – near the present NSW and Queensland border – and south of there, on the Liverpool Plains.

For example, in 1888 he was staying at the Picton Arms Hotel, in Campbell Street Sydney not too far from Redfern where the Mudgee train terminated at that time.'.

In 1892, at the time of the birth of their son, Hugh Alton Chandos, his wife, Mary née Hunt was living in Glebe, NSW.

"[35] Leo was correct and although the Australian Joint Stock Bank was eventually wound up by its fixed deposit holders and creditors only at a meeting in London on 22 March 1910, it had been in a continuing scheme of arrangement since 1893,[36] when it took the action which sent Wall bankrupt.