James Sinclair was born in Caithness, Scotland in 1817. He moved to Wellington in 1852 with his wife, child and nurse who was specifically selected for her plainess so as not to attract a husband. Sinclair then set up shop in Nelson selling goods he had brought with him from Manchester. The nurse, who had adapted well to colonial life and had given considerable assistance to the Sinclairs suddenly announced her marriage to a Mr. Brindle who had set his cap at her.
James Sinclair moved to Wairau in 1852, not long after the Wairau Massacre and settled at Boulder Bank. After only a short time there Mrs. Sinclair complained about the loutish behavior of Wynen's patrons and so they resettled at Beaverton. Even with the tense relations between Europeans and Maori, Sinclair "prefered to live near 'the more respectable Maori" and soon gained their confidence though his scrupulous honesty. Soon after he arrived he built Wairau's first wooden house as well as a row of buildings along the edge of the Opawa River including a bank, Victoria Hotel and a general store. This was partly a practical objection the argument that there were not enough houses in Blenheim for it to be provincial capital. Through his many businesses, Sinclair amassed considerable wealth which he used for the benefit of the district. He was renowned for being clear headed, very strong minded and having an immense amount of determination and energy giving him the necessary drive to see Marlborough separated from Nelson. He died two years after his wife in 1897 aged 79 with a reputation for, above all, always having his door open to both poor and rich.