New Immigrants and Old. Americans at the turn of the century were alarmed about what they perceived as a change in the type of immigrants entering the United States. Some of the traits they saw as distinguishing the new immigrants from the old immigrants were real; some were imagined; some were half-true. The old immigration peaked in the 1880s. The new immigration peaked in 1907.
It is absolutely OK to filter and reuse deep-fry oil. It's not uncommon at some short-order restaurants for them to filter the oil daily and only change it once a week. Of course, it does start to taste a little off when you reuse it that many times.
There's some good news, then some bad news, then more good news again, in that order. Good News A: You don't have to throw out used oil. Often you can reuse it many, many times! Bad News: There's no hard and fast rule for how many time you can reuse that oil. Distrust any source that gives a firm answer on the number times you can reuse oil, including this site.