请问这句话如何理解?

songxiaoshiUID: 3170134

But it was only in the early 1930’s that federal legislation prohibiting a company from maintaining its own unions with company money eventually allowed the Brotherhood to become recognized as the porters’ representative.
这句话怎么理解呢?翻来过去看么有看懂.哪位g友帮忙看一下.
整段话如下:
When A. Philip Randolph assumed the leadership of the Brotherhood of Sleeping Car (sleeping car: 卧车) Porters, he began a ten-year battle to win recognition from the Pullman (Pullman: n.卧车, 普式火车(19世纪美国发明家George M.Pullman设计的豪华型列车车厢,常用为特等客车)) Company, the largest private employer of Black people in the United States and the company that controlled the railroad industry’s sleeping car (sleeping car: 卧车)
and parlor (a room used primarily for conversation or the reception of guests: parlor car: n.特等豪华铁路客车) service. In 1935 the Brotherhood became the first Black union recognized by a major corporation. Randolph’s efforts in the battle helped transform the attitude of Black workers toward unions and toward themselves as an identifiable group; eventually, Randolph helped to weaken organized labor’s antagonism toward Black workers.
In the Pullman contest Randolph faced formidable obstacles. The first was Black workers’ understandable skepticism toward unions, which had historically barred Black workers from membership. An additional obstacle was the union that Pullman itself had formed, which weakened support among Black workers for an independent entity.
The Brotherhood possessed a number of advantages, however, including Randolph’s own tactical abilities. In 1928 he took the bold step of threatening a strike against Pullman. Such a threat, on a national scale, under Black leadership, helped replace the stereotype of the Black worker as servant with the image of the Black worker as wage earner (wage earner: n.靠工资为生的人, 雇佣劳动者). In addition, the porters’ very isolation aided the Brotherhood. Porters were scattered throughout the country, sleeping in dormitories in Black communities; their segregated life protected the union’s internal communications from interception. That the porters were a homogeneous group working for a single employer with single labor policy, thus
sharing the same grievances from city to city, also strengthened the Brotherhood and encouraged racial identity and solidarity as well. But it was only in the early 1930’s that federal legislation prohibiting a company from maintaining its own unions with company money eventually allowed the Brotherhood to become recognized as the porters’ representative.
Not content with this triumph, Randolph brought the Brotherhood into the American Federation of Labor, where it became the equal of the Federation’s 105 other unions. He reasoned that as a member union, the Brotherhood would be in a better position to exert pressure on member unions that practiced race restrictions. Such restrictions were eventually found unconstitutional in 1944.
来自gmat阅读.
O(∩_∩)O谢谢

popol1991UID: 3285073

But it was only in the early 1930’s that federal legislation prohibiting a company from maintaining its own unions with company money eventually allowed the Brotherhood to become recognized as the porters’ representative.
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但是，就是因为1930年早期的（联邦立法阻止公司使用个体资产成立个体联盟）最终促成了Brotherhood被认可为工人代表。
括号里整个是一个名词性成分，当然，句子强调的是1930年的那个时间，可能我翻译的不太到位，但大概意思是这样……

songxiaoshiUID: 3170134

2# popol1991 谢谢你!我觉得你翻译得很好!