Born into a wealthy English family, Edward and his elder brother Henry received a good education but were orphaned at a young age.

They initially spent time with a relative in the Hawke's Bay Region from whom Edward learned photography.

They were involved in a very public scandal in 1876 when Edward beat a prominent member of parliament to some land that they were both interested in based on insider information that had been passed on by his brother.

Edward Sealy explored in the Southern Alps, sometimes working alongside Julius von Haast.

[4][5] The brothers' intention was to proceed to Hawke's Bay but the ship lay in Lyttelton Port for a month as much of the crew had deserted.

[1] In mid-February, they set off from Wellington on the Emily Allison to meet up with their relative Henry Bowman Sealy, who lived at Patoka, inland from Napier.

In 1874, the brothers won a tender for a survey contract further west and inland, with Edward working in the area near Burkes Pass.

This happened just prior to Henry finishing a contract survey of Saint Andrews township; this was completed on 9 May 1876.

[13] Sealy's uncle in Patoka is assumed to have been the first commercial portrait photographer in New Zealand, advertising his trade in 1848.

[17] It is estimated that Sealy's gear that he carried onto the glaciers for photography weighed 60 pounds (27 kg).

[2] When the New Zealand Alpine Club was founded in Christchurch in July 1891, Sealy was elected as one of the vice-presidents.

Insects in his collection from overseas were from India, Africa, China, New Guinea, Malaysia, Mexico, Ecuador, Brazil, Peru, and Guiana.

On 13 October 1873, he married Frances Sarah Sanderson (born 21 September 1855) at the family's homestead, Greta Peaks, near Scargill in the Hurunui District.

Henry Sealy and his wife Emma were living with them until their adjacent house, 'Heathcliffe', was ready by November that year.

[21] Sealy cut his leg with a sickle during the time of the Richardson scandal in 1876 and spent a month in bed.

[2][24][25] In its obituary, The Timaru Herald described his exploration in the Southern Alps thus: The courage, determination and coolness required to pack a heavy photographic apparatus over the glaciers and make good use of it, in the days before Swiss guides, ropes and ice-axes were thought of in New Zealand, mark a man of the sterling stamp required for successful pioneering.His wife died at 'Southerndown' on 4 January 1912 aged 56.

[29] His eldest child, Violet (1875–1926), married Charles James Peter on 21 December 1898 at St Mary's Church in Timaru.

[31] Sealy's collections of moths, butterflies, and birds' eggs are held by the South Canterbury Museum in Timaru.

[34] When his granddaughter Audrey Barker died in February 1935, the Church of the Good Shepherd at Lake Tekapo was under construction.