20) what group of immigrants arrived in large numbers on the u. s. west coast for the primary purpose of working on the transcontinental railroad in the 19th century?

1960: wilma rudolph was the first woman to win three olympic gold medals in track and field at one olympic games. she was an american sprinter from tennessee, she was acclaimed the fastest woman in the world. she was among the most visible black women in america and abroad. she became a role model for black and female athletes. she was also known as a civil rights and women right's pioneer.

1973: billy jean king is an american former number one tennis player. she represented the united states in the federal cup and the wightman cup. for three years she was the usa's captain in the federation cup. she defends gender equality and has been a pioneer for equal and social justice. at the age of 29, she won "the battle of sexes" tennis match against the 55 year old bobby riggs. she was also the founder of women's tennis association and the women's sports foundation.  

1983: tamara mckinney becomes the first american female skier to win the alpine world cup overall championship top. she was the only american to hold that title for a quarter century until 2008.

1992: manon rhéaume, from canada,   becomes the only woman to start in a national hockey league game in an exhibition game for the tampa bay lightning . she played on the canada women's national ice hockey team winning gold medals in 1992 and 1994. and silver medals in 1998. manon marked the first time a woman appeared in a regular season professional game with her first appearance against the salt lake golden eagles.

2013: serena williams won 78 of 82 matches at the age of 31. she is an american professional tennis player. she reached the number 1 ranking for the first time on july, 8, 2002. at the age of 16, she played against karsten braasch the battle of sexes. she was the highest paid female athlete in 2016. she is a unicef ambassador .

1. ford: gerald ford´s presidency, from 1974 to 1977, faced high inflation, named it public enemy nº1, and created the win program (whip inflation now).

2. carter: president from 1977 to 1981, carter had controversial poitions over abortion, but yet, he enforce the roe vs wade decision, which had pro-choice content.

3. reagan. for his eloquency and powerful speeches in his mandates, from 1981 to 1989, reagan earned this nickname, “the great communicator” .

4. george h w bush: despite many presidents had important roles in managing and trying to end the cold war, it was in bush sr's mandate that the berlin wall was materially destroyed, and he was visited by gorbachev in the uspresident from 1989 to 1993.

5. clinton: defense of marriage act. clinton signed this controvesial act, which defined marriage and spouses in strict heterosexual perspective, that was later declard unconstitutional by the us supreme court.

6. george w bush: in the begining of his presidency, which lasted until 2009, bush jr faced the greatest terrorist attacks in us and probably the worlds history, in september, 11 of 2001.

7. obama: in attempts to cease a great economical crisis, barack obama signed the controversial recovery act in february 2009, which handled 780-billion dollars.