1800s
The Alexander family and their descendants owned and lived in the area. In the early 19th century the Alexandria and Washington Turnpike was built along the eastern boundary (Route 1). Most of the land was undeveloped or had agricultural use.
 
1845
A race course was built north of Mt. Ida Avenue. The St. Asaph Race Track was incorporated in 1888, with legal betting.
 
1850
Railroad tracks laid through the area.
 
1870s
Several farmhouses built on the former Alexander land.
 
1894
The 254 acres comprising the communities of Del Ray and St. Elmo were sold to developer Charles Wood  for the sum of $38,900, while St. Elmo, made up of 39 acres, was purchased for $15,314.
 
1900s
At the turn of the century, Del Ray contained approximately 130 persons and St. Elmo 55.
 
1908
The tracts of Del Ray, St. Elmo, Mt. Ida, and Hume were incorporated into the town of Potomac, which by 1910 had a population of 599.
 
1930
The Town of Potomac annexed by the City of Alexandria. It now has 2,355 residents. About a third of the residents walked to work at the nearby Potomac Yards, a major railroad switching facility.
 
1940s and 50s
Residents commuted by train or trolley to jobs in Alexandria and with the expanding Federal government in the District. 

1990s
Del Ray begins experiencing substantial gentrification as the redevelopment of Potomac Yard takes shape. Potomac Yard has future development plans for condominiums, parks, and a fire station with affordable housing on upper floors.

1996
St. Elmos Coffee Pub opens, becoming an anchor for the community. Founder and owner Nora Partlow is often called Del Ray’s unofficial mayor.

2008
On May 3, Del Ray celebrates its Centennial, starting at Monroe and Commonwealth Avenues marching to the Mount Vernon Recreation Center fields. A historic float will be built by the community, and anyone who wears a period hat may walk in the parade. The parade will have at least one antique car for each decade, and will end at the Mount Vernon Rec fields for the battle of the bands and a May Pole.