Trying to get a feel for the pattern of cold winters in the eastern US for the past 100 or so years.
Certainly three periods stand out: the legendary winter of 1899 still holds the crown as the single worse regional cold spell in modern history: downtown DC's all time record low of -15F, Baltimore's of -7F, and Florida's only subzero record at -2F. In terms of overall periods, the two leaders are the early 1930s, and 1977-1985, ending with the locally famous Reagan inauguration freeze, one of the last times central DC went below 0F. In 1932, College Park, Maryland hit an astonishing -26F! Much closer to DC than Dulles airport's -18F all time record low in 1984. Baltimore hit -7F again in 1934.
Other periods I can find: the winter of 1961 has records for several areas and dates. 1994 and to some degree 1996. 1918, 1905, and 1957 were cold, too. Generally speaking, you hardly see any cold records for the 20s, 40s, and 60s other than 61.

However here in the upper Bay region of Maryland, an elderly neighbor who moved here in 1960, tells me winters used to much colder. That people used to skate on a local pond that I haven't seen anywhere close to fully & safely frozen at all in the past 8 years. Also her recollection doesn't exactly jibe with what I know about the history of camellias at the National Arboretum. Many plants planted in the 50s and 60s died in the winters of the late 70s. So were winters before the 1990s colder on average, but, other than the big freezes of the late 70s and mid 80s, less prone to severe sub 0F freezing?

http://www.sercc.com/climateinfo/historical/historical.html

Once you click on a location, the "Daily Summary Stats" are particularly useful, in additional to the general temperature summary page.