A Vision of Britain through Time provides the following description of Haddington from John Marius Wilson's Imperial Gazetteer of England and Wales of 1870-72:
Since 1931 Haddington has been part of the civil parish of Aubourn Haddington and South Hykeham (which became only Aubourn and Haddington in 1991). It contains a mixture of houses and farm buildings, all brick built, and stands on the north bank of the River Witham 200m from the river. It is situated just off the Fosse Way Roman road, now the A46 road, 7 miles (11 km) southwest from Lincoln and 1 mile (1.6 km) west from Aubourn.
Prior to 1974 Haddington was located in Branston Rural District (1894-1931) and, as part of Aubourn Haddington and South Hykeham, in North Kesteven Rural District (1931-1974). The area is now covered by the North Kesteven District. (Source: Wikipedia)
Lincolnshire is very low-lying and land had to be drained for agriculture to be successful. The larger drainage channels, many of which are parallel to each other, became boundaries between parishes. Many parishes are long and thin for this reason.
There is much fenland in Lincolnshire, particularly in the Boston and Horncastle areas. Fenlands tended to be extraparochial before the mid 1850s, and although many sections were identified with names and given the title "civil parish", little information has been found about them. Many appear to be abolished in 1906, but the parish which adopts them is not given in A Vision of Britain through Time. Note the WR category Lincolnshire Fenland Settlements which is an attempt to organize them into one list.
From 1889 until 1974 Lincolnshire was divided into three administrative counties: Parts of Holland, Parts of Kesteven and Parts of Lindsey. These formal names do not fit with modern grammatical usage, but that is what they were, nonetheless. In 1974 the northern section of Lindsey, along with the East Riding of Yorkshire, became the short-lived county of Humberside. In 1996 Humberside was abolished and the area previously in Lincolnshire was made into the two "unitary authorities" of North Lincolnshire and North East Lincolnshire. The remainder of Lincolnshire was divided into "non-metropolitan districts" or "district municipalities" in 1974. Towns, villages and parishes are all listed under Lincolnshire, but the present-day districts are also given so that places in this large county can more easily be located and linked to their wider neighbourhoods. See the WR placepage Lincolnshire, England and the smaller divisions for further explanation.