Main Street is not really one street but two, joined in the middle at the Market Square. Lower Main Street runs from the Oldtown Road roundabout at the south end up the hill toward the square; Upper Main Street continues from the square to Crossview House at the top. Traffic flows one-way southward from Crossview down to Oldtown Road. The lower half is the older shopping quarter, with banks at the Market Square junction and the Letterkenny Library and Arts Centre about halfway down. The upper half is the older social quarter - the Central Bar, in business since 1808, is here, as is R. McCullagh Jewellers from 1869 and Magees Pharmacy from 1928. The post office sits above Magees. The whole length climbs and falls along the gentle ridge that the town was built on.

Twice a year - in May and in November - the corner of Upper Main Street at Speer's Lane filled with children. The hiring fairs, locally called Rabble Days, were the day on which boys and girls between the ages of eleven and sixteen were lined up to be hired for six-month terms by wealthy farmers from the Laggan district in east Donegal. They walked in from outlying villages, sometimes in bare feet. They stood in rows. A farmer would inspect a child, ask questions, perhaps feel an arm for strength, and offer wages. The hire ran until the next fair. Children far from home often slept in barns. The system continued in Letterkenny well into the twentieth century. In December 1994, the sculptor Maurice Harron's bronze statue *Rabble Children* was placed at the Market Square - small figures of girls and boys carrying their few possessions in cloth bundles - the town's quiet acknowledgement of what once happened on its main street.

Main Street has its anchors of history at both ends. At the south end, the Wolfe Tone Bar marks the spot where the United Irishmen leader was held before being sent to die. The bar occupies the site of the old Royal Irish Constabulary barracks, in continuous use from the 1850s until the RIC was dissolved in 1922 and replaced by the Garda Síochána. At the upper end, the spire of St Eunan's Cathedral rises 240 feet above the town - the most expensive church ever built in Ireland - making Main Street effectively the connector between two of Donegal's most charged historical sites: the place where Irish republicanism was imprisoned and the place where Irish Catholicism built its most ambitious monument.

Drive Upper Main Street slowly and you can read a hundred years of family business in the signage. Magees Pharmacy from 1928. R. McCullagh Jewellers from 1869. The Central Bar from 1808. McGarrigles Shoes from 1981 - which announced its closure in April 2023. Donegal Stationery from 1912. Speers Department Store, one of Letterkenny's oldest, still operates on Lower Main. But the *Donegal News* counted around forty vacant commercial properties along Main Street in early 2020, before the pandemic, and the number has not dramatically improved since. The retail centre of the town has shifted out to ring-road developments and the Courtyard Shopping Centre, whose unusual spiral architecture - descending into a hillside via escalators - has its main entrance halfway up the lower street. The traditional Main Street remains the social heart of Letterkenny, but the shopping has gone elsewhere.

On 3 May 2019, the 114th Infantry Battalion of the Irish Army marched in formation through the Market Square and along Main Street on parade. They were on their way to a UNIFIL deployment in southern Lebanon, Ireland's largest overseas military mission. The Defence Forces chose Letterkenny for the send-off in recognition of one specific fact: County Donegal had contributed more soldiers to the mission than any other county, while many UNIFIL battalions historically draw heavily from Dublin and Leinster. Hundreds of townspeople lined the pavements. The parade began on the playing fields at St Eunan's College and worked its way through. For a single morning, the long street, claimed as the longest in Ireland, was again what it had been for two hundred years - a public stage on which the town saw itself and its history walk past.