(CNN) Even before US President Donald Trump took office, lesbian, gay, bisexual and transgender Americans feared his administration would roll back gains they made in the Obama administration.

Now, 100 days into Trump's presidency, advocacy groups say their concerns have been realized through Cabinet appointments and policy decisions that undermine civil rights for LGBT Americans.

Here's a timeline of key actions affecting LGBT Americans from the first 100 days.

Reversing course

February 10: In the first sign of a new Justice Department with different priorities, the agency dropped its defense of Obama-era protections for transgender students in a key lawsuit.

After the departments of Education and Justice issued joint guidance in May 2016 directing schools to let transgender students use facilities that correspond with their gender identity, officials in a dozen states sued to block their implementation.

A federal judge in Texas granted the states' request for a nationwide injunction to halt the guidelines' enforcement. The Obama administration's Justice Department appealed to reduce the injunction's scope to states involved in the lawsuit while the case was alive.

Then, the day after Attorney General Jeff Sessions was sworn in, the Justice Department said it withdrew its appeal so it could decide how to "best proceed" with the lawsuit.

February 22: A few weeks later, the Trump administration A few weeks later, the Trump administration withdrew the guidelines entirely, in a joint decision from the departments of Justice and Education.

JUST WATCHED Protections pulled from trans school restrooms Replay More Videos ... MUST WATCH Protections pulled from trans school restrooms 02:46

March 27: Trump signed an executive order that nullified an Trump signed an executive order that nullified an Obama administration initiative to ensure that federal contractors complied with labor and civil rights laws forbidding discrimination based on sexual orientation and gender identity.

March 28: Meanwhile, the Obama administration's efforts to collect data on LGBT Americans had begun to unravel.

Advocates have long pushed for the government to gather data on LGBT Americans, including how numerous they are. There's no official national count of gay, bisexual or transgender Americans. Therefore, advocates welcomed the inclusion of "sexual orientation" and "gender identity" in the Census Bureau's road map for 2020 data collection. But celebrations were premature. The agency later said it found "no need" to collect the data.

The reversal came days after Secretary Tom Price's Department of Health and Human Services eliminated questions about about sexual orientation and gender identity in proposed versions of two critical health-care surveys addressing the needs of the elderly and the disabled

Advocates said their inclusion in surveys helps assess needs within the LGBT community and collect data to support policy changes.

April 14: After North Carolina After North Carolina repealed and replaced its so-called bathroom bill with another measure that prevents cities from passing anti-discrimination ordinances, the Justice Department halted its litigation related to the laws.

Meanwhile, a handful of state and district courts have sided with transgender students in lawsuits against schools. And, observers are waiting to see what's next for transgender teen Gavin Grimm's lawsuit against the Gloucester County School Board in Virginia. The withdrawal of the guidance led the Supreme Court to return the case to a lower court to consider whether anti-discrimination protections extend to gender identity.

JUST WATCHED The teen at the center of the transgender bathroom debate Replay More Videos ... MUST WATCH The teen at the center of the transgender bathroom debate 01:34

Trump's appointments

Presidential appointments speak volumes about what an administration will stand for, said Sharon McGowan, director of strategy at legal aid group Lambda Legal.

Attorney General Jeff Sessions was sworn in February 8.

LGBT advocacy groups opposed the nominations of then-US Sen. Jeff Sessions and then-US Rep. Tom Price to head the Justice Department and Department of Health and Human Services based on their legislative track records on gay rights issues.

As lawmakers, both supported a constitutional ban on same-sex marriage in 2006, though Sessions promised in his confirmation hearings that he would follow the Supreme Court's decision on marriage equality. It didn't come up in Price's hearings, and observers are waiting to see whether he upholds anti-discimination measures in the Affordable Health Care Act that protect LGBT Americans.

Health and Human Services Secretary Tom Price, left, with US President Donald Trump and Vice President Mike Pence.

When in Congress, Sessions and Price co-sponsored the First Amendment Defense Act, the so-called religious liberty bill preventing the federal government from punishing businesses for denying services to same-sex couples. They voted against expanding federal hate crime statutes to include sexual orientation, gender and disability. They condemned the repeal of "don't ask, don't tell," the policy that forbade gay and lesbian service members from serving openly.

LGBT advocates are concerned about the White House appointment of former Heritage Foundation employee Roger Severino to lead the Health and Human Services civil rights office. He came out against a provision of the Affordable Care Act banning discrimination against transgender patients, saying the rule would "threaten the religious liberty, freedom of conscience, and independent medical judgment of health care professionals."

JUST WATCHED Transgender identity, in their words Replay More Videos ... MUST WATCH Transgender identity, in their words 02:44

The road ahead

From the President to the attorney general to Education Secretary Betsy DeVos, the administration has said it's trying to balance civil rights with states' right to set their own policies.

But advocacy groups say the administration's actions are efforts to erase them from America narrative.

"One hundred days of Trump translates into 100 days of erasure for the LGBTQ community," said Sarah Kate Ellis, president and CEO of advocacy group GLAAD.

"From the census exclusion, to rescinding Obama's guidance for trans youth in schools, and lack of any LGBTQ mentions on the White House website, he has spent the early days of his administration trying to remove us from the very fabric of this country, and we must resist."