Partnered with the 格助詞（かくじょし） (case-marking particle) に, the う-Verb 渡（わた）る ‘to cross’ in its て-form highlights a span of something in regard to breadth, size, or time. This structure is often translated as either ‘across (A)’, ‘throughout (A)’, ‘extending through (A)’. or ‘over the period of (A)’.
Like other verb structures that pair with nouns, the standard form may also be used when paired with a second noun, in order to modify that noun.
He continued to hide from the police for many years after his escape.
A war that has been taking place for over fifteen years has finally come to its end.
Coming from the meaning of 渡（わた）る ‘to cross’, this grammar pattern always expresses that something is either happening or exists ‘all across (A)’, or ‘from the start to the finish’. Additionally, に渡（わた）って
is considered quite formal, so will often be seen in articles or on the news.
Caution - As 渡（わた）る indicates a span of something that is being crossed, the ‘span’ must always be indicated clearly.
The meeting that has been going on throughout the whole morning has finally ended.
The stock of Company A has finally risen after going down over the span of tonight.