The line originally consists of routes X1, X2, X3, X4, X5, X6, and X7 all operating under former streetcar lines. Afterwards the DC Transit company took over operating buses along H Street and Benning Road. Then WMATA took over DC Transit on December 4, 1973 and incorporated the X1, X2, X3, X4, X5, X6, X7, X8, and X9.[2]
Route X1 operated between Minnesota Avenue station and Potomac Park via Washington Union Station, Louisiana Avenue, and Constitution Avenue. Route X2 operated between Minnesota Avenue and Union station. Route X3 operated between Minnesota Avenue and McLean Gardens. Route X4 was a new route introduced on November 24, 1978 operating between Minnesota Avenue and Lafayette Square. Route X5 was designated as "Owl Trips" operating between Seat Pleasant, Maryland and Lafayette Square. Route X6 would operate between Lafayette Square and Mayfair.[3] All these routes mostly operate along Benning Road and H Street.
In the 1980s, route X5 and X7 were discontinued and replaced by routes X1, X2, X3, X4, and X6. No major changes were made to route.
In the 1990s, routes X3, X4, and X6 were discontinued and replaced by routes X1, and X2. Route X2 was also split from the Benning Road Line and was formed into the Benning Road-H Street Line operating on the former X4 and X6 routing between Minnesota Avenue station and Lafayette Square. Routes X1 and X3 were unaffected by any changes and continue to operate on its same routing.
On June 25, 2000, route X3 was reincarnated to operate alongside the X1 between Minnesota Avenue station and McLean Gardens during the weekday peak-hours.[4]
On December 19, 2010, route X1 was extended from Potomac Park to Foggy Bottom–GWU station via 23rd Street.[5]
In 2012, routes 96 and X3 were extended from McLean Gardens to Tenleytown–AU station adding additional service along Wisconsin Avenue NW from McLean Gardens due to a long-term detour route in 2012 to accommodate construction of Cathedral Commons.[6]
In 2015 during WMATA's FY2017 budget, WMATA proposed to shorten route X3 at Duke Ellington Bridge due to low ridership between both Duke Ellington Bridge and Tenleytown–AU station since route X3 operates parallel to routes 30N, 30S, 31, 33, 96, H2, H3, and H4.[7][8]
On June 26, 2016, route X3 was shortened from Tenleytown–AU station to Duke Ellington Bridge due to low ridership between the two points.[9] Alternative service is provided by route 96.
During WMATA's FY2021 budget, it was proposed to eliminate routes X1 and X3 completely due to low ridership. The X3 trip from KIPP DC College Prep school would still operate however. Replacement service would be provided by an extended route X8 to Foggy Bottom–GWU station during the weekday peak-hours for X1 while routes X2, X9, and DC Streetcar covers most of X1 and X3 routing along H Street and Minnesota Avenue station. Routes 90, 92, and 96 also operates on most of X3's routing as well. WMATA proposed the elimination due to the availability of alternative service, including proposed extension of some route X8 weekday peak trips to Potomac Park and Foggy Bottom.[10]
According to performance measures, it goes as the following:[11]
| Route | Average Daily Passengers | Passengers Per Trip | Passengers Per Revenue Mile | Passengers Per Revenue Hour | Max Load (% of Seats) |
| September 2017 | X1
X3 | 744
500 | 41.4
35.7 | 6.3
5.9 | 37.8
32.2 | 37 (90%)
45 (109%) |
| September 2018 | X1
X3 | 698
469 | 41.1
33.5 | 6.2
5.5 | 47.4
35.5 | 39 (94%)
32 (80%) |
| September 2019 | X1
X3 | 697
460 | 41.0
32.9 | 6.2
5.4 | 47.2
36.6 | 41 (105%)
30 (77%) |
According to WMATA, 501 riders (42%) would still be able to make exact same trips on other services, 666 riders (56%) would require one additional transfer to complete current trip, and 22 riders (2%) may have to walk an additional 0.2 miles to a bus stop. The impacts of service proposal on the current riders by route segment are as follows according to WMATA:[11]
| Alternative Service | Passengers Impacted | Impact |
| X1 passengers between Minnesota Avenue station and North Capitol Street & Massachusetts Ave NW | X2, X9 (80, D8 on North Capitol Street) | 302 (43% of X1) | Exact same trip can be made on alternate services. |
| X1 passengers between North Capitol Street & Massachusetts Avenue NW and Potomac Park/Foggy Bottom-GWU station | X8 extended trips to Potomac Park/Foggy Bottom-GWU Station[R1 - 1] | 396 (57% of X1) | One transfer would be required to complete the trip. |
| X3 passengers between Minnesota Avenue station and Florida Avenue & Holbrook Street NE[R1 - 2] | X2, X9 | 72 (16% of X3) | Exact same trip can be made on an alternate services. |
| X3 passengers on Florida Avenue between Holbrook Street NE and 8th Street NE[R1 - 3] | None | 22 (5% of X3) | Some riders would have to walk up to 0.2 miles to an alternate stop. |
| X3 passengers between Florida Avenue & 8th Street NE and Duke Ellington Bridge | 90, 92 | 270 (59% of X3) | One transfer would be required to complete the trip. |
| X3 passengers with trips entirely west of New Jersey Avenue | 96 | 69 (15% of X3) | Exact same trip can be made on alternate services. |
| X3 passengers with trips entirely east of Bladensburg Road | X2, X9 | 58 (13% of X3) | Exact same trip can be made on alternate services. |
WMATA would later back out the proposal on April 2, 2020 due to customer pushback.[12][13][14][15]
On March 16, 2020, all route X1 and X3 service was suspended in response to the COVID-19 pandemic and WMATA switching to a supplemental schedule during the weekdays.[16]
The proposed elimination was brought back up on September 26, 2020 due to low federal funding. Routes X1 and X3 has not operated since March 13, 2020 due to Metro's response to the COVID-19 pandemic.[17]
On March 14, 2021, route X3's school trip to KIPP College Prep was restored and will operate between the school and Minnesota Avenue station. The full route remained suspended, however.[18][19]
By September 5, 2021, Routes X1 and the full X3 route were eliminated. Route X3's school trip to KIPP remained in service, running during every school year when school was in session until the final day of the 2024-2025 year (June 13, 2025) before being fully discontinued as part of WMATA's Better Bus Network Redesign on June 29, 2025.[20]
