According to the United States Census Bureau, the city has a total area of 2.2 square miles (5.7 km²), of which, 2.1 square miles (5.5 km²) of it is land and 0.1 square miles (0.1 km²) of it (2.28%) is water.
Flower came to America in 1816. He and Morris Birkbeck, another Englishman, met and agreed to explore the western country with the idea of starting a colony of their own countrymen. After a long journey through Ohio, Indiana, and the Illinois Territory, they were so impressed with the beauty of the countryside around Boultinghouse Prairie that they knew they had found what they were looking for. They bought all the land they could afford, and eventually brought over from England more than 200 settlers, £100,000 in capital, and a carefully thought out selection of livestock and agricultural implements. The area became known as the English Settlement.
In 1824, the county seat of Edwards County was moved from Palmyra to Albion. Residents of Mount Carmel felt the county seat should be in Mount Carmel and not Albion. Four companies of militia marched from Mount Carmel toward Albion to seize the county documents stored in the courthouse. The situation was resolved by separating Wabash County from Edwards County at the Bon Pas Creek in 1824. The divided counties remain two of the smallest in Illinois.
There were 861 households out of which 26.7% had children under the age of 18 living with them, 51.5% were married couples living together, 9.5% had a female householder with no husband present, and 37.4% were non-families. 34.5% of all households were made up of individuals and 19.4% had someone living alone who was 65 years of age or older. The average household size was 2.20 and the average family size was 2.82.
In the city the population was spread out with 21.6% under the age of 18, 7.3% from 18 to 24, 24.0% from 25 to 44, 22.8% from 45 to 64, and 24.3% who were 65 years of age or older. The median age was 43 years. For every 100 females there were 83.7 males. For every 100 females age 18 and over, there were 80.3 males.
The median income for a household in the city was $29,476, and the median income for a family was $36,917. Males had a median income of $26,182 versus $17,375 for females. The per capita income for the city was $14,747. About 8.6% of families and 12.2% of the population were below the poverty line, including 19.0% of those under age 18 and 9.3% of those age 65 or over.