This started out as a "Talk of the Nation" topic the other day: Books
you've read that no one else has.

I've got one that I know my sister read and forgot, but I can't for
the life of me remember the name of it. I read it in the mid-to late
nineteen eighties. It was the first book I'd read that had the
beginning at the end, and opened a whole new way of telling stories to
me.

The bare details I recall are a heroine named Rose, stepping onto a
train in the first chapter. The time was the late 1800's and it
covered her role and maturity as a daughter, wife, and mother as a
Jewish(?) immigrant in New York in the garment industry and the
associated trials and tribulations.

She worked in a coat(?) factory and got involved in unionising the
workers along with a young man that she later married. He (I think)
was killed in the riots/uprising surrounding that unionisation ... and
I recall before they married a confrontation with her father ... he
was being unreasonable about them marrying until she started
apologising at the top of her lungs so it would 'look better to the
neighbors'.

Hello.

Your book is "One Way to Ansonia" (1985) by Judie Angell.

See this description from the Library of Congress
"At the turn of the century, ten-year-old Rose immigrates from Russia
to America and eventually finds that her emergence into adolescence
brings employment, marriage, motherhood, and self-determination."
Source: Library of Congress catalog entry 
http://catalog.loc.gov/cgi-bin/Pwebrecon.cgi?v3=1&DB=local&CMD=010a+85005652&CNT=10+records+per+page

The book has all of the elements that you describe. Additionally, the
part about the train trip is confirmed in this description:
"The story of Rose, one of a large Russian Jewish immigrant family,
begins as she buys a ticket to Ansonia at Grand Central Station in
1899."
NYCbooks.tripod.com, cached by Google (warning: page may be hard to
read with using certain browsers)
http://216.239.51.100/search?q=cache:13m4nJgBz7gC:nycbooks.tripod.com/historical-fiction-1800s.htm=en&ie=UTF-8&client=googlet


About 20 copies of "One Way to Ansonia" are currently for sale on
Alibris, a listing service for used books:
http://www.alibris.com/search/search.cfm?qwork=4855584&matches=19&qsort=r

There are also some very inexpensive copies listed on half.com:
http://half.ebay.com/cat/buy/prod.cgi?cpid=3051945

search strategy: library of congress catalog terms: rose, jews,
fiction

I hope this helps.

I've been going NUTS trying to find it, using all of the keywords I
could think of on various search sites. I came up with excellent
non-fiction books that describe similarly named women and
circumstances ... wow. Thank you very very much.

Judie Angell is a really nice lady too. I wrote to her when I was 12
after reading her "In Summertime It's Tuffy" about a zillion times:)
She wrote me back a letter (which I still have!) and was so gracious
and sweet.