By the mid 19th century the development of the village was accelerating. An 1845 directory of the county includes a description of the village:
The chief agricultural productions are corn and potatoes, with market gardening carried on to a considerable extent, particularly for strawberries. There is a blacking manufactory and a steel mill. The labouring population are chiefly nailers, working in their own cottages.
Nailmakers are first recorded in Harborne in a legal document of 1600, but it had been an established occupation in these parts for many years before. Often it would be an alternative employment to agricultural labouring when the weather prevented working on the land. The whole family might be involved, helping at the small forge built to the side or rear of the cottage. Iron was supplied by the nail masters, a few of whom were among the wealthier residents of Harborne. A finished load of nails might have to be carried into Birmingham to be exchanged for the raw material to fashion the next load.
Harborne also had a reputation for laundresses. Perhaps the proximity of wealthier Edgbaston guaranteed a demand for such work. The Census of 1851 provides plenty of evidence of both nailmakers and laundresses, and of the young age at which schooling might be abandoned to take a place at the forge. However, by this time, nailmaking on this small scale was in a decline, and would soon have disappeared completely.
The opening of the railway line in 1874 signalled the start of more development to the north of the High Street. Although the trains still passed the fields of Hill Top Farm as they left the village, the importance of agriculture to its economy was waning. Small businesses and light industry were on the increase.
In 1888 The Greater Birmingham Scheme was drawn up, to include the annexation of Harborne. Harborne ratepayers voted to oppose this. Most issues of local government were the responsibility of the Local Board, and the rate levied on the residents was favourable.
The following year a further attempt was also rejected. But in 1890, after a rise in local rates, and the promise of increased policing, improved pavements and street lighting, and the provision of a free library, a resolution in favour of annexation was passed. This occurred the following year, heralding in a new phase in Harborne's development as it made ready to enter the twentieth century.
The Masonic Hall of 1870 was converted into Harborne Library by Birmingham Corporation in 1892. It underwent a major refurbishment in 2006.