In 1911, Georgia Avenue was proposed as a state highway between the Washington, D.C. border and Brookeville.
This section of state highway was completed by 1915.
By 1921, a state highway was proposed between Roxbury Mills and Cooksville, with a small piece completed to the south of Cooksville.
Also, a state highway was completed between Westminster and the Pennsylvania border, connecting to a road that continued northwest to Gettysburg, Pennsylvania.
By 1923, the state road was finished between south of Cooksville and north of Roxbury Mills and to the north of Cooksville.
With the creation of the U.S. Highway System on November 11, 1926, the portion of present-day MD 97 north of Westminster was designated as part of US 140, a U.S. Highway that ran from Baltimore to Gettysburg.
In addition, the portion of Georgia Avenue between Norbeck and Olney was designated as part of MD 28 in 1927.
The state highway was completed south to Roxbury Mills in 1928.
By 1933, the state road between Brookeville and Roxbury Mills was finished.

MD 97 was designated by 1933 to run from MD 27/MD 410 (now US 29) in Silver Spring to north of US 40 (now MD 144) in Cooksville.
 In 1935, a state highway was finished south of the MD 26 west Eldersburg and heading south from MD 32 in Fenby.
Both these highways were extended south about 0.5 miles (0.80 km) in 1938.
In 1939, the state highway running south from MD 26 west of Eldersburg and from MD 32 south of Fenby were both designated as MD 570.
By 1946, the MD 28 concurrency between Norbeck and Olney was removed.
The southern section of MD 570 was extended south 0.5 miles (0.80 km) again in 1948.
MD 97 was widened into a divided highway between Silver Spring and Glenmont in 1950.

In 1956, MD 97 was extended north to the Pennsylvania border northwest of Emmitsburg, Frederick County.
The route ran north from Cooksville to Fenby, replacing both sections of MD 570, before it replaced MD 32 from Fenby north to Westminster and northwest through Taneytown and Emmitsburg.
In 1960, MD 97 was moved to a new alignment that bypassed Westminster along newly constructed New Washington Road between Fenby and US 140 and the Westminster Bypass to the northwest side of the city.
MD 32 was designated onto the former alignment of MD 97 that passed through Westminster on Washington Road and Main Street.
In 1961, MD 97 was shifted to a new alignment to the east between MD 26 and MD 32; the former alignment became MD 854.
The intersection with MD 26 was replaced with an interchange in 1962.
In 1964, construction began on a new alignment of MD 97 slightly to the north between Westminster and Taneytown.
This alignment was completed in 1965, and the former alignment became a part of MD 32 (now MD 832).
In 1966, the divided highway portion of MD 97 was extended north from Glenmont to MD 28 in Norbeck.

In 1977, plans were made for US 140 to be decommissioned, with MD 97 to replace the section between Westminster and the Pennsylvania border, where it would connect to PA 97.
This proposal was made in order to eliminate short routes from the U.S. Highway System.
The American Association of State Highway and Transportation Officials approved the removal of the US 140 designation on October 28, 1977.
On January 1, 1979, MD 97 was rerouted at Westminster to head north to the Pennsylvania border, replacing US 140.
At the Pennsylvania border, the route connected to PA 97, which replaced the US 140 designation in Pennsylvania.
Meanwhile, the former alignment of MD 97 between Westminster and the Pennsylvania border northwest of Emmitsburg became a part of MD 140.
Dualization of MD 97 in Montgomery County was extended further north from MD 28 to MD 108 by 1989.
There are plans to build an interchange at the route’s intersection with Randolph Road in order to improve movements for automobiles as well as for pedestrians and bicycles accessing the nearby Glenmont Metro station.
Another new interchange was built with MD 200 (Intercounty Connector) north of MD 28 and opened on February 23, 2011.

On September 25, 2018, a groundbreaking was held f
In 1911, Georgia Avenue was proposed as a state highway between the Washington, D.C. border and Brookeville. This section of state highway was completed by 1915. By 1921, a state highway was proposed between Roxbury Mills and Cooksville, with a small piece completed to the south of Cooksville. Also, a state highway was completed between Westminster and the Pennsylvania border, connecting to a road that continued northwest to Gettysburg, Pennsylvania. By 1923, the state road was finished between south of Cooksville and north of Roxbury Mills and to the north of Cooksville. With the creation of the U.S. Highway System on November 11, 1926, the portion of present-day MD 97 north of Westminster was designated as part of US 140, a U.S. Highway that ran from Baltimore to Gettysburg. In addition, the portion of Georgia Avenue between Norbeck and Olney was designated as part of MD 28 in 1927. The state highway was completed south to Roxbury Mills in 1928. By 1933, the state road between Brookeville and Roxbury Mills was finished.
MD 97 was designated by 1933 to run from MD 27/MD 410 (now US 29) in Silver Spring to north of US 40 (now MD 144) in Cooksville.  In 1935, a state highway was finished south of the MD 26 west Eldersburg and heading south from MD 32 in Fenby. Both these highways were extended south about 0.5 miles (0.80 km) in 1938. In 1939, the state highway running south from MD 26 west of Eldersburg and from MD 32 south of Fenby were both designated as MD 570. By 1946, the MD 28 concurrency between Norbeck and Olney was removed. The southern section of MD 570 was extended south 0.5 miles (0.80 km) again in 1948. MD 97 was widened into a divided highway between Silver Spring and Glenmont in 1950.
In 1956, MD 97 was extended north to the Pennsylvania border northwest of Emmitsburg, Frederick County. The route ran north from Cooksville to Fenby, replacing both sections of MD 570, before it replaced MD 32 from Fenby north to Westminster and northwest through Taneytown and Emmitsburg. In 1960, MD 97 was moved to a new alignment that bypassed Westminster along newly constructed New Washington Road between Fenby and US 140 and the Westminster Bypass to the northwest side of the city. MD 32 was designated onto the former alignment of MD 97 that passed through Westminster on Washington Road and Main Street. In 1961, MD 97 was shifted to a new alignment to the east between MD 26 and MD 32; the former alignment became MD 854. The intersection with MD 26 was replaced with an interchange in 1962. In 1964, construction began on a new alignment of MD 97 slightly to the north between Westminster and Taneytown. This alignment was completed in 1965, and the former alignment became a part of MD 32 (now MD 832). In 1966, the divided highway portion of MD 97 was extended north from Glenmont to MD 28 in Norbeck.
In 1977, plans were made for US 140 to be decommissioned, with MD 97 to replace the section between Westminster and the Pennsylvania border, where it would connect to PA 97. This proposal was made in order to eliminate short routes from the U.S. Highway System. The American Association of State Highway and Transportation Officials approved the removal of the US 140 designation on October 28, 1977. On January 1, 1979, MD 97 was rerouted at Westminster to head north to the Pennsylvania border, replacing US 140. At the Pennsylvania border, the route connected to PA 97, which replaced the US 140 designation in Pennsylvania. Meanwhile, the former alignment of MD 97 between Westminster and the Pennsylvania border northwest of Emmitsburg became a part of MD 140. Dualization of MD 97 in Montgomery County was extended further north from MD 28 to MD 108 by 1989. There are plans to build an interchange at the route’s intersection with Randolph Road in order to improve movements for automobiles as well as for pedestrians and bicycles accessing the nearby Glenmont Metro station. Another new interchange was built with MD 200 (Intercounty Connector) north of MD 28 and opened on February 23, 2011.
On September 25, 2018, a groundbreaking was held f
Maryland Route 97