Trolley Line Number 9 Trail

Mount Gilboa Chapel is a historic African Methodist Episcopal Church located in Oella, Maryland, United States. It is a small stone church measuring 28 feet by 42 feet, built about 1859 by free African Americans. The front façade is ashlar masonry, but the sides and rear are of rubble.

Oella is a mill town on the Patapsco River in western Baltimore County, Maryland, United States, located between Catonsville and Ellicott City. It is a 19th-century village of millworkers' homes.

Ellicott's Mills Historic District is a national historic district at Oella, Baltimore County, Maryland, United States. It is on the east bank of the Patapsco River, opposite Ellicott City. This historic district designation relates to the industrial operations of the Ellicott family from the 1770s through the mid-19th century. It consists of the sites of historic buildings including: an 18th-century building, a section of an 18th-century mill incorporated in a 20th-century factory, a 19th-century tavern, 19th-century workers housing, and an 1859 Italianate villa built by John Ellicott. Historically, these industrious mills were served by the major east–west route in Maryland during the early 19th century, the old National Pike. Also in the district is the mammoth multi-story Wilkins-Rogers Company flour plant, which is located on the site of the 1792 Ellicott Flour Mill, the first merchant flour mill in the United States.It was added to the National Register of Historic Places in 1976.

George Ellicott House is a historic house located in Oella in Baltimore County, Maryland, United States. George Ellicott was a son of Andrew Ellicott, one of several brothers that founded Ellicott Mills (Ellicott City). George Ellicott bought swampland after the colonial war now known as the Inner Harbor of Baltimore. He used a horse drawn dredge to create shipping docks for his flour supplies.The George Ellicott House was built in Oella on the eastern shore of the Patapsco River opposite Ellicott City. The granite house was built in 1789. It resided on the grounds of the Wilkens-Rodgers flour mill. In 1972 the house was flooded by Hurricane Agnes and his brother Jonathan's neighboring house was destroyed. In 1983 the Maryland General assembly contributed $135,000 toward the $1 million expense of moving the house to higher ground on the other side of the street it resided on. The move was facilitated by a partnership between Historic Ellicott City Inc., James A. Clark, Jr., Judge John L Clark, and the Oella Company.

The Patapsco Hotel is historic granite building located in Ellicott City, Maryland, on the western bank of the Patapsco River. The current Patapsco Hotel is built with materials from an older granite construction hotel on the same site and is known as the Thomas' Patapsco Hotel, Wilson Patapsco Hotel, Stewart's Hotel, and McGowan's Hotel. The original Thomas' Hotel was four stories tall made of local quarried granite stone block. The rear wall of the first floor is imbedded into a solid granite hillside. It served as a stagecoach stop along the National Pike road. The hotel was later called Stewart's Hotel featuring a bar and bowling alley. In 1806, Chief Little Turtle of the Miami people, Chief of the Rusheville people, Beaver Crow of the Delawares, Chiefs of the Shawanese, and the chief Raven of the Potowatomies visited George Ellicott staying at his home and the Hotel while returning from a visit to Washington, D.C. The second floor balcony led to and served as an unloading terminal for the B&O Railroad at Ellicott's Mills. Henry Clay once performed a speech from the balcony during a presidential campaign. During the civil war, the hotel was considered a host of Southern Sedition. The hotel operated as late as 1879. For a period the hotel was used for an ice house for a period. In 1920, the hotel owned by Hezekiah I Thomas was not in use with the windows broken and the county condemned the property. In 1926, a wall adjacent to the railroad collapsed, causing streetcar service to be halted. Passenger cars had to halt as an inspector checked for enlargement of cracks before they could pass the building. A 12-bay-wide, four-bay-deep three-story building was constructed on the same site with the same granite stones named the Patapsco Hotel. The original foundation was used, including some standing walls. The building was converted into an apartment house in the 1940s. The building now houses shops on the bottom floor and apartments above. The property later was purchased by Samuel H. Caplan, who operated several long-standing businesses in Ellicott City.

Lilburn Cottages are a group of historic cottages part of Liburn Mansion, located in Ellicott City, Howard County, Maryland. The cottages were built on an original 2,500-acre land grant named the Valley of Owen. The Gothic Revival Lilburn Mansion was built on College Avenue for Baltimore foundry owner Henry Richard Hazlehurst in 1857. The original 20-acre site has been subdivided down to 8 acres, and the guesthouse and carport outbuildings demolished. The site of the cottages was subdivided into a 6.75-acre parcel, which allowed the portion of the historic Lilburn complex to fall outside of the Ellicott City Historic district development protections.In 2013, owners Ronald and Gail Spahn allowed the Howard County Department of Fire and Rescue Services to burn the historic structures, including the adjacent Lilburn (Hammond) Cottage and Grimes house, before subdividing the property. Spahn's Autumn Development Corporation used Howard County slope stabilization legislation to help fund clearing the historic wooded site for single-family homes. KB homes marketed the subdivision as Autumn Overlook.

The Baltimore and Ohio Ellicott City Station Museum in Ellicott City, Maryland, is the oldest remaining passenger railway station in the United States, and one of the oldest in the world. It was built in 1830 as the terminus of the Baltimore and Ohio Railroad line from Baltimore to the town then called Ellicott's Mills, and a facility to service steam locomotives at the end of the 13-mile (21 km) run. The station, a National Historic Landmark, is now used as a museum.

The Oaks is a historic home and slave plantation located in Ellicott City, Howard County, Maryland (considered Elkridge, near Ellicott's Mills when built). The house is situated on a land tract named Joshua's Addition patented in 1723 by Joshua Sewall fronting an Indian trail latter named Claggett Road. In 1778 Thomas Cockey sold the land to John Merriken. The land passed to Caleb Dorsey who sold it to the Hare family in 1840. The property featured a cedar tree walkway dated to 1789. An original eighteenth-century stone house was modified to a flat-roofed Italiante structure in 1856 by ship captain Robert H Hare, who also built and lived at the Linwood building. In 1864, Jehanne Elvira Hopkins moved from the South with her slaves and bought the land including Mt. Misery and Oeall Enlarged. A tenant house and slave quarters collapsed in the 1960s. On May 14, 2015, a fire broke out in the structure at 11 am.

Saint Paul Catholic Church is a Catholic parish located in Ellicott City, Maryland. It was founded in 1838 and is part of the Archdiocese of Baltimore. Babe Ruth married here. It is a two-story ashlar granite church which faces north. It is three bays wide and four bays deep. Its front facade includes two twin Roman arch windows each topped by a rose window, enclosed within a Roman arch lintel with keystone.

Mt Ida is a historic home in Ellicott City, Howard County, Maryland. Mt. Ida was built for William Ellicott, grandson of one of the city's founding brothers, Andrew Ellicott in 1828. It was built by Charles Timanus, who was also the principal builder of the neighboring Patapsco Female Institute and the Howard County Courthouse. Judge John Snowden Tyson and family lived at the residence from the 1850s, with his daughter Ida Tyson, for whom the mansion is now named, remaining in the house until the age of 90 in the 1920s. Ownership passed hands again to John Ward Wilson, then the influential Clark Family Commissioner Charles E. Miller attempted to rezone the property to convert the mansion into office buildings in 1972. As of 2013, the mansion was owned by the Miller Land Company.

Patapsco Female Institute (PFI) is a former girls' boarding school, now a partially rebuilt historical site, located on Church Road in Ellicott City, Maryland, United States. The grounds are home to popular outdoor theatrical performances by The Chesapeake Shakespeare Company. In the 1930s the Institute was also known as "Warwick".

Lilburn Mansion, also known as the Balderstones Mansion or Hazeldene is a historic home located in Ellicott City, Howard County, Maryland. The site of the structure is on an original 2,500-acre land grant named the Valley of Owen. The gothic revival mansion was built on College avenue for Baltimore foundry owner Henry Richard Hazlehurst in 1857. The house has architectural features that included a bell tower and solarium. A 1923 fire destroyed the front parlor and interior. The original 20 acres site has been subdivided down to 8 acres with the guesthouse and carport outbuildings demolished.In later years, the mansion has been popularized by haunted house storytellers.