The linen industry was an important one in Ireland during the 18th and 19th centuries, and many families were involved in either the spinning of flax into yarn, or in the bleaching of the linen. The background on the bleaching greens and the families in the parish of Aghadowey, Co. Londonderry that ran them during that period, can be found here:

Bleaching was done at the bleaching greens. A linen bleaching green consisted of central housing for bleaching and finishing, with lands extending up to 25 or 30 acres on which to spread the linen. In the days of water power, there would be a carry or lead to bring the water to the water wheels.

The older O.S. maps show the lands used for spreading linen, and at times the positions of the watch houses used by the watchmen guarding it. As to the buildings, the most important housed the washmill and the beetling machinery, and these are closely described in the 0.S. Memoirs. The Memoirs say:

“It may be added that to each (bleach green) is attached a drying house and a lapping room. The former is in general 30 feet to fifty feet long, with large latticed windows on each side to admit the fresh air upon the linen.”

To identify the bleach greens mentioned in deeds and newspaper advertisements is not as easy as it seems. With their large spreading fields they often extended to two townlands, and they were sometimes given names differing from the townlands in which they stood. Mullamore green is in fact in the townland of Mullahinch, now in the townland of Mullaghmore. Greenfield is part of the townland of Mullan in Aghadowey parish, and to make matters worse there is another Greenfield bleach green in Macosquin parish which again does not correspond to ;an actual townland.

Abbreviated details of the bleach green on the Aghadowey, from rootsweb.com

Aghadowey

Townland of Aghadowey. Run by Abraham Browne in 1782, may have been succeeded by his sons Andrew or Robert, green failed under Brownes. In 1816 linen buyers in Coleraine were Hemphill and McFarland, Aghadowey. In 1835 it was part of property of Greenfield bleaching company of Hunter, Hemphill and McFarland, with two slated houses, three wheels and 25 acres. Wooden bridge connecting it with Greenfield green on the other side of river built 1810. Mortgaged 1853 by Curtis Hemphill of Greenfield and Wm. Hemphill of Flowerfield to Alex. Hurley of Coleraine. In 1859 occupied by James Smith & Co. In 1864 James McFarland, the younger, of Newry, gentleman, renounced absolutely his claim to this green. An old house among briars and bushes still to be seen, entrance past Bellevue House, owned by Mr. H. Morrison. (Reg. of Deeds 1853.25.154,1857.31.90, 1864.30.186).

From rootsweb.com