The point mapped is actually the address of Angell Hall. Angell Hall is an academic building at the University of Michigan in Ann Arbor. It was previously connected to the University Hall building, which was replaced by Mason Hall and Haven Hall. Angell Hall is named in honor of James Burrill Angell, who was the University's president from 1871-1909. http://en.wikipedia.org/wiki/Angell_Hall University Hall North wing (Mason Hall) built in 1840, South wing (South College) built in 1848, Central wing built in 1871.

n 1879, the Pavilion Hall was built. It included a glass conservatory and was also used for concerts and social events. Oscar Wilde gave a lecture here in May 1882. The Hall burned down in 1902. It was replaced by the existing Victorian style conservatory known as the Palm House in 1910. \ http://en.wikipedia.org/wiki/Allan_Gardens 

December 8 and 9, 1884 and February 14, 1885

Once Rochester's premier lecture hall, site of addresses by such luminaries as abolitionists Susan B. Anthony and William Lloyd Garrison, Ralph Waldo Emerson, Horace Greeley, and many others.  

Joe Vogel on January 5, 2012 at 4:52 am  The Majestic Theatre was an extensive rebuilding of the Utica Opera House, which had been built in 1871. When Sam Shubert took over the lease on the Opera House in 1900, he had the building largely gutted and expanded to create a space for a more modern theater. In addition to the new Majestic, the building housed a second-floor assembly room at the Washington Street corner of the structure, and this was converted into the Orpheum Theatre in 1901. 

Twain and Cable played at the Grand Opera House in Syracuse but it was not at the Wieting Opera House. The attached clippings, provided me by Kimberly Kleinhans, librarian, Local History/Genealogy, Onondaga County Public Library, describe the offerings at both venues.

Next door to the Sprague Block, on the southwest corner of State and Tioga, stood the Wilgus Block (1868). Brothers John M. Wilgus, an architect, and Henry L. Wilgus, a real estate dealer, built the Wilgus Block on the site of Dwight Tavern, an early "publick house." Wilcox and Porter of Buffalo designed the building. The Wilgus Opera House, seating 1600 people, occupied the third and fourth floors. Retail stores occupied the first floor, offices the second. The opera house was Ithaca's main entertainment center until the Lyceum Theater was built on South Cayuga Street in 1893.

The Troy Savings Bank was founded in 1823 and moved to its current location in 1870. In appreciation of the community's support, the plans for the new building called for a music hall to be built on the upper floors. In the early years of the 20th century the Music Hall featured performances from artists such as Lillian Nordica, Henri Vieuxtemps, Ignace Jan Paderewski, Albert Spalding, Sergei Rachmaninoff, Myra Hess and Jose Iturbi. In the 1930s and 1940s, artists including Vladimir Horowitz, Yehudi Menuhin and Artur Rubinstein played there.

The local newspaper of record in the 1880s was the Jerseyman. I searched the Friday after Thanksgiving in 1884 but failed to find an article about Twain and Cable speaking here or staying with Thomas Nast. However, I found the following brief article on the previous Friday, the 21st an page 2 at the bottom of the 4th column: 

10th & G St NW, November 24 & 25, 1884 and February 28, 1885, the final show of the tour. 

in May 1868, the congregation moved into its new home at 10th and G St. NW. Its large brick building made a statement. The Congregationalists were here to stay.