Ong himself was a prominent Kapitan Cina to the Hokkien community of Sarawak, and a successful businessman in multiple fields.

Venturing into business at such a young age, he had to turn to an older man, Lim Eng Moh, for guidance.

Throwing caution to the wind, he joined Lim in setting out to the newly-established state of Sarawak to seek his fortune.

One of the firm's main businesses was transporting sago starch from Mukah to Kuching, pre-processed and also the trade of gambier and pepper.

His close relationship Sir James Brooke earned Ewe Hai the appointment of Kapitan Cina.

There is a total of six roads in Kuching, Sarawak named after generations of the Ong family, mostly by the Rajah in recognition of their contribution to the community.

[3] He never forgot his Singaporean roots, and probably intended to retire there as he built a fine residence which he called Bonnie Grass.