What do these headlines say about how the supreme court has addressed the principle of equality on which the united states was founded?

The answer is: They showed that the court has enforced equal rights for a variety of groups that have been discriminated against.

Prior to the civil rights act, the supreme court openly discriminate their decisions against minorities.

To justify their actions, the highlight how the constitution only intended to support 'citizens' while the minorities at that time were not considered to be one. They started to change their opinion regarding this issue after several headlines were made by journalists to address their decisions.

this is a pretty broad question and can be a pretty lengthy answer. since 1900, women have gained a lot more rights and have become active in the workforce. with women being in the workforce, men play a larger role in family life. many family tasks are shared between men and women, whereas, women used to be the sole family caretakers.

that should get you started at least.