In 1840, the steam-powered Annapolis and Elk Ridge Railroad (A&ER) was built across a sparsely settled farming community that would later become Odenton. At the beginning of the American Civil War Union soldiers guarded this railroad line because it was the only link between the North and the nation's capital. Rail traffic through Baltimore had been disrupted by southern sympathizers, so supplies, mail and soldiers flowed through Annapolis and West Anne Arundel County to Washington, DC. The town of Odenton, nicknamed "The Town A Railroad Built" by Catherine L. O'Malley, ^[1] was formed in 1868 with the construction of the Baltimore Potomac (B&P) Railroad connecting Baltimore and Washington, D. C.. Where the B&P crossed the A&ER, a train station and telegraph office were constructed and named for Oden Bowie, President of the B&P and former governor of Maryland. Train service to the station began on July 2, 1872. The rail junction (today's MARC station) at Odenton Road, already a busy thoroughfare from Annapolis to Frederick, became the site of Odenton's first commercial center. The Watts and Murray general stores served railroad workers and farmers and in 1871, a post office was established. A town grew near the junction, houses were built for railroad workers, a Methodist church was dedicated in 1891 and a grade school opened in 1892.

Small villages developed around these various railroad lines, but none amounted to more than a cluster of shops and homes around a train station and post office. The 1878 Maryland Directory listed the following towns: Conaway, Odenton, Patuxent, Sappington, and Woodwardville. Odenton was the largest with a population of 100 with a church and school, and two stores. In nearby Woodwardville, where the B&P crossed the Little Patuxent River, A. G. Woodward was the postmaster and operated a general merchandise store in a village of 50 people. Two churches and a school served that community. Land was worth from $5 and $30 per acre, producing wheat, corn and tobacco.

In recent years the Odenton area has become the fastest growing area in the county. This is because of its location near Ft. George Meade, NSA.  Headquarters, and its proximity to Baltimore Washington, D.C., and Annapolis. The development has been fueled by the construction of the massive Piney Orchard development as well as the soon to be under-construction Odenton Town Center.

Odenton is represented in the Maryland General Assembly by legislators in Districts 21 and 33. District 21 is primarily in Prince George's County. District 33 also includes Severna Park, Crownsville and Crofton. Odenton is represented in the Anne Arundel County Council in District 4 by Jamie Benoit.

There were 7,594 households out of which 37.7% had children under the age of 18 living with them, 58.8% were married couples living together, 10.5% had a female householder with no husband present, and 26.9% were non-families. 19.7% of all households were made up of individuals and 4.2% had someone living alone who was 65 years of age or older. The average household size was 2.70 and the average family size was 3.13.

The median income for a household in the CDP was $65,563, and the median income for a family was $69,098. Males had a median income of $45,965 versus $32,659 for females. The per capita income for the CDP was $26,124. About 1.6% of families and 2.5% of the population were below the poverty line including 1.8% of those under age 18 and 5.2% of those age 65 or over.