英语的语法问题 来人啊

most of whom were born before 1835 定语从句,
practiced 和后面的and were securely established...句子的谓语
用and来连接
in a mode在一个模式，什么模式？
self -taught and monopolized by landscape subject matter 作后置定语修饰mode

年长的画家，他们中的大部分人都是在1835年之前出生，在一个通常是无师自通和受景观主题垄断的模式中练习，并由统治美国艺术组织，国家设计学院安全地安顿和培养。

后边n个分句都是描述older painter的 可以看为排比句
1practiced in a mode often self -taught and 2monopolized by landscape subject matter
3were securely established in and 4fostered by the reigning American art
organization, the National Academy of Design.

and是连接词 可以理解为；号

这其实就是由一系列的从句构成的长句。self taught 前面省略了which was 。self taught 和 后面的这一串句子都是来说明 mode的。

The older painters, most of whom were born before 1835, practiced in a mode.是主句。后面的成分都是mode的修饰语。