In the 1970s Mrs Mary Ellen Maclaurin left money in her will for the building of an art gallery in Ayr or for the purchase of a suitable building for that purpose. It was to be called The Maclaurin Art Gallery in memory of her husband. Provision was also made for the purchase of exhibits. The money was used to convert the stable wing of Rozelle House into a contemporary exhibition space and a purchasing committee was set up. Over the years, the committee, advised by experts and supported financially by the Local Museum Purchase Fund, has built up one of the country's best collections of 20th century art, enhanced by donations from the Contemporary Art Society and individual artists.
One example of the important acquisitions made by the Maclaurin Trust is a painting by British painter Bridget Riley (b.1931) which was purchased in the late 1980s following an exhibition of her work organised by the South West Galleries Association in 1986. This was an informal grouping of six galleries in the south-west of Scotland and the Glasgow area that came together to share resources, co-ordinate activities and to present a major exhibition each year. The six galleries involved were the Dick Institute, the Maclaurin Galleries, Gracefield Arts Centre, the McLean Museum and Art Gallery in Greenock, the Lillie Art Gallery in Milngavie and Paisley Museum and Art Gallery.