The procedure for appointing a Justice to the Supreme Court of the United States is provided for by the Constitution in only a few words. The "Appointments Clause" (Article II, Section 2, clause 2) states that the President "shall nominate, and by and with the Advice and Consent of the Senate shall appoint ... Judges of the supreme Court." The process of appointing Justices has undergone changes over two centuries, but its most basic feature—the sharing of power between the President and Senate—has remained unchanged. To receive a lifetime appointment to the Court, a candidate must first be nominated by the President and then confirmed by the Senate. The most recent vacancy on the Court was created by the death of Justice Antonin Scalia on February 13, 2016. In response, President Barack Obama on March 16, 2016, nominated Merrick B. Garland, a sitting judge on the U.S. Court of Appeals for the District of Columbia, to replace Justice Scalia. It was the 161 st nomination made by a President to the U.S. Supreme Court. On the day of Justice Scalia's death, Majority Leader Mitch McConnell (R-KY) stated that the "American people should have a voice in the selection of their next Supreme Court Justice. Therefore, this vacancy should not be filled until we have a new President." Additionally, Senator Chuck Grassley (R-IA), chairman of the Senate Judiciary Committee, stated "Given the huge divide in the country, ... it only makes sense that we defer to the American people who will elect a new president to select the next Supreme Court Justice." In response, Minority Leader Harry Reid (D-NV) stated that "The president can and should send the Senate a nominee right away.... Failing to fill this vacancy would be a shameful abdication of one of the Senate's most essential Constitutional responsibilities." President Obama also weighed in on whether the Garland nomination should be considered by the Senate, asking that the Senate "give him a fair hearing and then an up or down vote," while also stating that "I have fulfilled my constitutional duty. Now it's time for the Senate to do theirs." The Garland nomination was not acted upon by the Senate (receiving neither a committee hearing nor a floor vote) and was not withdrawn by the President—making it the first Supreme Court nomination since 1866 for which no formal Senate action was taken and which was not subsequently withdrawn or resubmitted by a President. The nomination was ultimately returned to President Obama at the end of the 114 th Congress, on January 3, 2017. On February 1, 2017, President Donald Trump nominated Neil M. Gorsuch, a sitting judge on the U.S. Court of Appeals for the Tenth Circuit, to fill the Scalia vacancy. The Gorsuch nomination, the 162 nd to the Court, is currently pending before the Senate. This report provides analysis and historical information related to several of the prominent issues or questions surrounding the Scalia vacancy. The issues addressed by the report include (1) how frequently vacancies occur on the Supreme Court, particularly vacancies created by the death of a sitting Justice; (2) how the length of the Scalia vacancy compares to past vacancies on the Court (as well as how the length of time the Garland nomination was pending before the Senate compares to past nominations); (3) how often vacancies on the Court arise during presidential election years (as well as how often vacancies on the Court have rolled over into a presidential election year from a preceding year); (4) how often vacancies on the Court have arisen during one presidency but are filled during a different presidency; and (5) how often vacancies on the Court have required multiple nominations prior to the appointment of a new Justice. Since President George Washington's initial six appointments to the Supreme Court in 1789 and 1790, a vacancy on the Court has occurred, on average, every two years. During the post-War period (1946 to the present), a vacancy on the Court has occurred, on average, every 2.4 years. In more recent years (since 1980), a vacancy has occurred, on average, slightly less frequently (every 3.1 years). The length of time, however, between the vacancy created by the retirement of Justice John Paul Stevens in 2010 and the vacancy created by Justice Scalia's death in 2016 is the fifth longest period of time between two vacancies ever occurring on the Court (specifically, 2,054 days, or 5.6 years, between the two vacancies occurring). Under the Constitution, Justices on the Supreme Court hold office "during good Behaviour," in effect typically receiving lifetime appointments to the Court. Once confirmed, Justices may hold office for as long as they live or until they voluntarily step down. Lifetime tenure, interesting work, and the prestige of the office often result in Justices choosing to serve on the Court for as long as possible. Consequently, it has not been unusual, historically, for Justices to die while in office. Specifically, of the 111 vacancies that have occurred on the Court during the past 225 years, from the first vacancy in 1791 to the vacancy created by Justice Antonin Scalia's death in 2016, 47 (or 42%) have arisen as the result of the death of a sitting Justice. Conversely, 64 (or 58%) of the vacancies since 1791 have occurred for some other reason (e.g., a new judgeship was created by Congress, a sitting Justice retired, or an Associate Justice was elevated to the Chief Justice position). Over the past 60 years, however, it has been relatively rare for vacancies on the Court to be created by the death of a Justice. Of the 25 vacancies on the Court since 1956, the vacancy created by the passing of Justice Scalia is only the second instance during this period of a vacancy created by the death of a Justice. Specifically, from 1956 to 2016, 2 (or 8%) of 25 vacancies were attributable to the death of a sitting Justice on the Court. Prior to the deaths of Justice Scalia (in 2016) and Chief Justice Rehnquist (in 2005), the last sitting Justice to die while serving on the Court was Justice Robert Jackson (in 1954). Prior to 1900, in contrast to more recent years, it was more common for vacancies to arise on the Court as a result of the death of a sitting Justice. Of the 51 vacancies on the Court that arose between 1791 and 1899, 30 (or 59%) arose in this manner. Additionally, of the 35 vacancies that occurred during approximately the first half of the 20 th century—from 1900 to 1955—15 (or 43%) of 35 arose as the result of the death of a Justice. On average, from the first vacancy that occurred in 1791 through the most recent vacancy filled in 2010 (by Elena Kagan), vacancies on the Supreme Court have lasted for 121 days (or approximately 4 months) before the Senate has approved a nominee (while the median length of time is 61 days, or 2 months, from a vacancy arising to a nominee being confirmed by the Senate). There is considerable variation, however, in how long vacancies have lasted. Vacancies on the Court, for example, have ranged from a minimum of 1 day to a maximum of 835 days (or 2.3 years). In general, vacancies on the Court lasted for longer periods of time prior to the 20 th century than during the 20 th or 21 st centuries. For example, prior to 1900, vacancies lasted an average of 165 days, or 5.4 months (with a median length of time of 105 days, or 3.5 months). In contrast, since 1900, vacancies on the Court have lasted an average of 77 days, or 2.5 months (with a median length of time of 46 days, or 1.5 months). As of March 1, 2017, the Scalia vacancy will have lasted for 382 days—making it currently the seventh longest vacancy in the history of the Court. Figure 3 shows the 10 longest vacancies to exist on the Supreme Court – 7 of which arose in the 1800s during the Civil War era or earlier. The Scalia vacancy is the longest of the 80 vacancies on the Court to have occurred since 1861. The one other vacancy since 1900 to be among the 10 longest vacancies on the Court is the vacancy created in 1969 by the resignation of Justice Abe Fortas, lasting 363 days (and which remains only one of two vacancies in the history of the Court for which the full Senate rejected two nominations in up-or-down votes on the floor). Of the 147 nominations made to the Court since 1791, the average length of time from nomination to final Senate action, whether such action was favorable or not in terms of approving the nomination, has been 28 days (while the median length of time to final action has been 12 days). There has been variation over time in how quickly nominations have been dispensed with, either favorably or unfavorably, by the Senate. For example, prior to 1900, nominations waited an average of 18 days for final Senate action (with a median wait time of 6 days). In contrast, since 1956, nominations have waited an average of 67 days for final Senate action, or 2.2 months (with a median wait time of 65.5 days). Along these lines, Figure 3 shows the 10 longest nominations pending for a vacancy on the Supreme Court since 1791 to the present. Eight of the 10 nominations listed in the figure have been for vacancies that have occurred since 1956. As discussed above, the Scalia vacancy is currently the seventh longest vacancy to exist on the Court. The first nomination submitted to fill the Scalia vacancy—the nomination of Judge Garland by President Obama—is the longest pending nomination for any Supreme Court vacancy since 1791.